10 ms·

The creator of Jujutsu has joined ERSC

265 points by steveklabnik 1mo ago

valvix 1mo ago
What a pivot, from manga to software
- deleted 1mo ago
  [deleted]
matthewbauer 1mo ago
Is this new? The date says July 8, 2026.
- steveklabnik 1mo ago
  Fixing, thank you! (Martin joined back then, but we are posting about it today, so we should have the post date as today)
steveklabnik 1mo ago
Working with Martin has been a real pleasure, and we'll have some more stuff to talk about very soon!
- opem 1mo ago
  excited for what you guys would be coming up with ;) btw, did Martin leave google?
  - steveklabnik 1mo ago
    Thanks! Martin left Google for this, yes.
    - underdeserver 1mo ago
      Wasn't it partially owned by Google? Or are they just a contributer now?
      - steveklabnik 1mo ago
        I like to compare Google and jj to Mozilla and Rust: Google employed Martin and some other maintainers, but it's always been an OSS project under the Apache 2.0 license. That being said, there's a few things that lead to this perception: the first is that it used to be under Google's GitHub account, but is now under its own org. The second is that contributing to jj does require signing Google's CLA. That is something that is desired to change, but that's up to Google. Due to the license, the community could fork it, and still have the rights to use the code, but that would be pretty aggressive, and so everyone involved would rather work together on this than do so. The move to its own GitHub org was one example of movement in that direction, but I'm not aware of an actual timeline to remove the CLA just yet. The project will figure it out over time. (I have a commit bit but am not a jj maintainer, so the above is my own impression from being involved in the community for the past few years.)
        underdeserver 1mo ago
        Thanks! Maybe if Martin could comment - his @google.com email still appears in the repo readme, I'm assuming he doesn't have access to that box anymore - was the repo move and ownership coordinated with Google prior to his leaving?
        martinvonz 1mo ago
        The move from martinvonz/jj to jj-vcs/jj happened almost two years ago. https://github.com/jj-vcs/jj/commit/b836e0ae9518154cd52f94e045bfe808b4471f1a https://github.com/jj-vcs/jj/commit/b836e0ae9518154cd52f94e0... (from 2024-12-17) says that it was recent at that time. Google were owners even when it was under martinvonz/jj, however.
        mcookly 1mo ago
- tcoff91 1mo ago
  I absolutely love jj (just check my HN comment history). One thing I'd love to see in jj though that git does better is copy tracking. If somebody renames a file upstream, and you go to rebase your commit that touches that file onto main, jj doesn't handle this very well compared to git. Do you have any idea if this is coming to jj soon?
  - steveklabnik 1mo ago
    There is active work in this area, yes! https://github.com/jj-vcs/jj/issues/3386 https://github.com/jj-vcs/jj/issues/3386 is the bug tracking the feature request, and there have been some recent PRs working on implementing this, see here for one example: https://github.com/jj-vcs/jj/pull/9864 https://github.com/jj-vcs/jj/pull/9864
  - drsouth 1mo ago
    Do you happen to have or know of any good open source projects on any public platform like GitHub, gitlab or Codeberg, that uses Jujutsu/jj?
    - nickisnoble 1mo ago
      It's hard to tell since any given dev can just use jj locally, if they want to, while everyone else uses git.
      - dzaima 1mo ago
        Technically, you can still tell actually - jj writes a "change-id xyz..." in the git commit object header, which remains there as it's pushed around. It's just typically not made visible by regular things. (I wonder what other random garbage has been hidden in git commit headers that noone has seen)
        OJFord 1mo ago
        Huh, fortunate for it that GitHub (especially) preserves it then! I wonder how guaranteed that is, can imagine GH deciding to 'clean' it (how much data can you put there theoretically? Or to close a range of potential security issues) and suddenly relatively niche but genuine uses like jj's change-id are unintentionally not preserved.
- drsouth 1mo ago
  Will this have any chance if Jujutsu/jj doesn't get more traction? The effort to learn a new VCS is less than for a programming language, but many developers have not learned git in depth, and Mercurial and others have not gained a lot of traction.
  - Kinrany 1mo ago
    It doesn't require that everyone switch at the same time, unlike other VCSs.
  - saghm 1mo ago
    I'd argue that the reason a lot of developers have not learned git in depth is because it's actually kind of terrible from a UX standpoint (lots of inconsistent naming of things and somewhat leaky abstractions), and that Mercurial faced an uphill battle in large part because it lacked compatibility with what people were already using. I haven't used Mercurial, but from what I've heard quite a lot of how jj does things is similar to Mercurial, just in a way that's compatible with git. I haven't used git directly for over a year in favor of using jj despite exclusively using git repositories, and no one I've worked with has even needed to be aware.
    - skydhash 1mo ago
      > I'd argue that the reason a lot of developers have not learned git in depth is because it's actually kind of terrible from a UX standpoint Not really. I remember my early years with git and the favt was that I never needed more than clone, add, commit, pull and push. While I’ve done some mistakes that got ne to learn more, especially with creating branches and undoing. I’ve never needed a lot, even when I started using GUI which exposed more concepts. Why? Because I have no understanding of version management and how it’s useful in a dev workflow/release process. I was just using it for checking in work. Since then, I’ve read the “Pro Git” book, learned how devs and teams handle versioning and devel a good understanding of how git can help me in my coding process and general software development. And it’s very good at what it does.
      - 1mo ago
tensegrist 1mo ago
what a lovely website
- steveklabnik 1mo ago
  Thank you! We liked our old look, but one funny thing about how things are going in the world: our old color scheme was too close to what happens when you ask Claude to generate a site, and so even though we paid a human to build it, we didn't want to communicate slop, especially because that's not what we did! Nick Noble is our designer, he put in a bunch of work on this, and I really like it too.
  - poly2it 1mo ago
    I love how little latency there is on your website. I'm often thrown off by websites freezing on navigation, something we euphemistically call "loading". I feel we should have moved beyond that in the year of 2026. Your website really respects the user in this regard. Aesthetics are splendid as well.
  - figbert 1mo ago
    Nick is great! Met him at the Recurse Center. Brilliant designer.
    - nickisnoble 1mo ago
      :octopus:!
- nickisnoble 1mo ago
  Thanks! There will be a lot more of it soon :D
  - spankibalt 1mo ago
    Hire somebody who's got at least a modicum of understanding of (web) typography. Small hint: A moving background layer makes reading supremely annoying, and for some people even (virtually) impossible.
RobotToaster 1mo ago
Jujutsu is apparently the name of a version control system, for anyone else confused how the creator of a thousand year old martial art had joined them.
- CobrastanJorji 1mo ago
  Thanks, I was trying to work it out in my head. I knew brazilian jiu jitsu was 20th century, and I was like "but wait, is jiu jitsu itself not that much older, that seems very surprising."
  - zerr 1mo ago
    Yeah. I thought maybe someone from Gracie family joined something :)
infogulch 1mo ago
What is ERSC?
- steveklabnik 1mo ago
  I wrote a bit about this here: https://news.ycombinator.com/item?id=49526190 https://news.ycombinator.com/item?id=49526190 I wrote about why I joined the company back when I did previously here: https://steveklabnik.com/writing/i-see-a-future-in-jj/ https://steveklabnik.com/writing/i-see-a-future-in-jj/ In short: we are building a next generation source control system for the enterprise.
fallat 1mo ago
Someone will have to explain the value proposition to me... We have git. jujutsu works with git. git can do everything jujutsu can do (otherwise, jujutsu couldn't work with git). Thus, jujutsu is a UX / new steering wheel. ERSC is trying to be a GitHub competitor with what surplus value? Don't get me wrong, GitHub has a slew of its own problems, but I have not seen any commentary on how ERSC addresses any of the downfalls GitHub has too. We're jumping from one frying pan into another, currently-cooler one? What about SourceHut? Codeberg? They could offer the same steering wheels. Edit: Thank you to everyone who replied. The enterprise/teams infrastructure angle makes sense.
- rirze 1mo ago
  I might be mistaken, but I always figured the end goal for jujitsu was to use its own backend. Supporting git-colocation seems like a compatibility case to bring users over. If I had to guess, then I would say ERSC is trying to build a `jj` forge based on this new hire and that would be amazing imo.
  - zmodem 1mo ago
    Maybe like some kind of https://jjhub.com https://jjhub.com :-)
- steveklabnik 1mo ago
  We'll be saying more about this very soon, but the short version is this: we are not building a GitHub competitor in the way that SourceHut or Codeberg are. We are building infrastructure for enterprises, not a social coding site. While jj works with git, it doesn't have to. jj has the ability to work with many backends. Git is the popular one in the open source world, but that doesn't mean that other ones are not possible. And that's the core tech we have built. With the rise of agents, more and more companies are running into the limits of what Git can do. It was never designed for large monorepos, and so there are performance issues, but also features that it's missing, that are important once you start trying to scale things up to an entire organization. Companies like Meta and Google ran into these things well before the present moment, but you don't have to be a FAANG these days to be running into this sort of stuff. We also understand that incremental adoption is really important, especially for something as fundamental as source control. So our tech also has a git ingress/egress that will work with the core functionality, but more advanced things that git simply can't do will end up requiring using a non-git protocol. jj is the bridge between those two worlds. I hope that makes sense! We have been in psudeo-stealth for a while now, this is the start of us coming out of our shell a bit and actually talking about what we're doing.
jph 1mo ago
Jujutsu is a better smarter git. It's a great convergence of better UX, plus more expressive, plus easier to use. If you haven't tried jj yet, take it for a spin and see how you like it.
- drsouth 1mo ago
  How does it compare to Mercurial? And why would it get more traction than Mercurial?
  - yegle 1mo ago
    Mercurial is too slow. Even with chg common commands like `hg status` may take hundreds of milliseconds. JJ is fast. Internally `jj log` taking more than 500ms is tracked as bugs.
    - drsouth 1mo ago
      [dead]
      - yegle 1mo ago
        Well I did not answer your second part of the question, only the first part of comparing Mercurial vs Git. Now to the second part: I think speed still plays a role back when Bitbucket and Google Code provides Mercurial hosting and people were comparing Mercurial with Git. Eventually GitHub won the competition, so then we kinda stuck with Git.
  - Arainach 1mo ago
    Git already won through Github, the Linux kernel, and other important projects. Even if you like Mercurial's syntax better (I do) and wish it won (I do), that battle was over many years ago. jj's data store is git. You can use jj while other people on your project just use git. There's no migration of data or history. You can use Github and all of the various git tooling that exists today. As such, the initial cost of switching to jj is zero for individuals, teams, or projects. That's huge. jj's ergonomics are significantly nicer. Fewer ways to shoot yourself in the foot, much better merge resolution, etc.
drcongo 1mo ago
This looks like excellent news.
medicalux 1mo ago
[flagged]
- swiftcoder 1mo ago
  Man, sockpuppet accounts on every rust-adjacent story on here are beyond tiresome. What does someone actually get out of being anti-rust?
  - fakoosu 1mo ago
    [flagged]
fenugurod 1mo ago
That’s amazing news. Can you share more about your tech stack? I suppose it’s mainly built with Rust?
- steveklabnik 1mo ago
  We have a colopholon! https://ersc.io/colophon https://ersc.io/colophon Rust is the default language for all of our non-frontend web stuff, yes.
ksymph 1mo ago
So if I understand correctly: ERSC is working on an alternative backend for jj other than git (and presumably providing related infrastructure)?
- yegle 1mo ago
  I think it's closer to: develop something similar to Google's Piper as (hopefully!) an open source project and sell this to enterprise, similar to Perforce's business model but with the benefit of an excellent and well received frontend tool.
KajMagnus 1mo ago
Congrats (or what's the right word :- )) Martin and best wishes to you and ERSC, Looking forward to using the VCS stuff you'll create :- )
waldrews 1mo ago
(off topic) why the headache-inducing animated background? An annoyance for all, and an actual accessibility issue for some.
- steveklabnik 1mo ago
  Not off topic! We should be respecting https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules/@media/prefers-reduced-motion https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/A... . If we do not, that's a bug, and please let me know what browser/OS/whatever else combo you have if that is an issue.
  - tefkah 1mo ago
    seems to respect reduce motion just fine! the animation, while extremely lovely, also does seem to be quite taxing on my GPU (~60% usage on M1 Max with Zen/Firefox, on a 1440p widescreen, which is admittedly quite a lot of space to render animation) love the website though, i hope i one day will be able to make something that elegant!
minraws 1mo ago
jj is one of the few new devtools I was quite frustrated with while starting out but could see the value so stuck around and man is it so nice. For anyone curious the big thing with jj is you can undo. Basically if you were running a rebase and bungled a commit sha or branch name, no worries undo your way out, if you forgot to push but abandoned a commit not issues undo it. Same with all jj commands. Delta db takes this a step further and everything you edit is a change so your actual edits are also all saved. I find non destructive-ness for as long as possible approach very nice, since there aren't as many constraints on us not being able to do it nowadays, we had limited storage and stuff in 2000s perhaps but in 2026 even with the killer SSD prices it's fairly cheap to buy more SSD, we can definitely waste 100MB per project storing redundant history we may not ever need. Same way in photoshop non destructive editing took over, especially useful for humans, but works for AI and LLMs too, they can undo their mistakes as well.
- sshine 1mo ago
  Are you saying push + undo = unpush?
  - yegle 1mo ago
    AFAIKT it will revert the local state to "pending push".
  - kps 1mo ago
    jj itself doesn't have a native ‘push’. `jj git push` and `jj piper upload`¹ operate on external systems that don't necessarily support undoing arbitrary operations. Pure speculation, but if I were ESRC I'd make my backend handle it (subject to enterprise audit policies). ¹ https://drive.google.com/file/d/1dVzug1lHoOxdbFu8gcCJCu-G_uVMUATI https://drive.google.com/file/d/1dVzug1lHoOxdbFu8gcCJCu-G_uV...
    - sshine 1mo ago
      Reminds me of the git-svn bridge. Points of no return.
  - 1mo ago
fakoosu 1mo ago
[flagged]
- sshine 1mo ago
  Without having tried JJ, as a hype chaser, I can say it's both worth it and not worth it. I run NixOS, work with Kubernetes, code Rust, use a 40% split, layered keyboard with Dvorak layout and open source firmware, kaj mi parolas Esperanton. They're just hobbies that, once you've sunk the hours in, they're awesome. I don't actually type faster. Or maybe I do type a little faster because it made me use all 12 fingers instead of the ad-hoc 7-finger system you taught yourself in primary school, but typing was never a bottleneck, and split keyboards actually hurt my wrists more. Jujutsu is marginally better than git, but costs time. If you like to spend the time, it will probably make you a little better. If you care deeply about your time, and it's already being allocated for anything but arbitrary intellectual pursuit, it's not worth it. Some people grow businesses, plants, or sedentary habits.
- skipants 1mo ago
  the person you responded to has been a user since 2019. why do you think they artificially push it? I also use jj as my daily driver now. I like it a lot. I have no skin in the game either.
phi-go 1mo ago
No word about the future of Jujutsu, so I guess this is bad news for for jj users?
- mtlynch 1mo ago
  Isn't ERSC aiming to be for jj what GitHub was for git? In which case, this would be great news for jj.
- steveklabnik 1mo ago
  It's in the post, but Martin will be continuing to work on jj itself as well as on our products, just as he did at Google, working on the open source jj but also their internal source control team. As a side note, jj has rules around company representation in maintainership, and so when this initially happened a few months back, ERSC actually became over-represented in the maintainers group, as we also employ several other maintainers. The project decided to add more maintainers to keep the balance, rather than ask folks to step down. We very much want to properly support the upstream project, and we want to make sure that it continues to be awesome for everyone, not just our customers.
  - sundarurfriend 1mo ago
    That idea about keeping maintainer balance is pretty neat, interesting to see this kind of diligence in maintainership in the same project where legal ownership belongs to a single company, Google, via the Contributor License Agreement. My interest in jj cooled off a lot after seeing that, even though I realize in practice it's pretty unlikely to be of consequence - I just don't need even that kind of low probability Sword of Damocles hanging over my VCS, forks and drama in case Google decides to mess things up. (Good to see that the Readme has been changed to say it's not a Google-supported project btw, less misleading than the old claim that it's not a Google project at all.)
    - steveklabnik 1mo ago
      Legal ownership does not belong to a single company. All copyrights are still held by each individual contributor, and they're available to be used under the Apache 2 license. The CLA means Google also has a license to the code to do what they will with it, but it does not do copyright assignment. They do not own your contributions.
mhd 1mo ago
"human ↔ machine collaboration" sounds rather creepy, to be honest.
- keeganpoppen 1mo ago
  tell that to Doug Englebart or J.C.R. Licklider-- the idea of human-computer symbiosis predates basically all computers that we would recognize as such today. crazy how it is only really now becoming true in the way that they envisaged in the 1960s.
drsouth 1mo ago
[flagged]
- steveklabnik 1mo ago
  I left a lengthy comment below about how we'll be supporting git as well. I have been a member of this community for a very long time. Posting here is something I just do. jj is already pretty well known here, there's articles about it quite often. But sure, I don't think that anyone would deny that a VC backed startup posting about their product to Hacker News has marketing value. You have to get the word out somehow. EDIT: oh, this person edited their comment after I replied. There's been a rash of these comments making wild, baseless accusations about Rust developers, thank you dang and the other mods for handling it.
  - junon 1mo ago
    I've met you (Steve) and hung out with him for a few hours after oxidize. He's none of those things, and in fact was one of the most pleasant people I've met at conferences. So not only are they brazen and vulgar allegations but I can't see even a distant parallel universe where they're even close to true. Super bizarre comment to see on HN.
tolerance 1mo ago
I'm way more interested in knowing what technologies Steve Klabnik is eyeing and planning to get involved with next.
- steveklabnik 1mo ago
  I joined ERSC ten months ago! The things I am most interested in right now are jj and llms. And the intersection between the two. I'm thinking a lot these days about how agentic development is changing our industry, with source control being one part of that.
nh2 1mo ago
This website has unbearable scroll performance on mobile. Is it the animation at the top?
- steveklabnik 1mo ago
  We tested it in mobile, but several people pointed out that we have more performance work to do to make sure that the animation is fast on lower-end hardware. I don't know what phone you're using, but we'll get it fixed regardless.
  - coffeeindex 1mo ago
    1 more data point - it's very slow on my desktop which has relatively high performance as well. Using Brave if that matters.
    - nickisnoble 1mo ago
      We're about to push a change that should improve this a bit, thanks for the reports!
      - nh2 1mo ago
        Thanks, the animation is gone now and the problems are gone as well. Good choice in my opinion, as I hadn't even noticed the animation existed until I looked for something that might make the scrolling slow.
  - usefulcat 1mo ago
    One more data point--I'm using Firefox on an M1 Mac mini (MacOS 15.7.7), and this web site destroys the responsiveness of this system in a way I have literally never seen before (4+ years) from anything, web site or otherwise. I opened up Activity Monitor and CPU use looked normal but it showed the GPU was pegged at 100% as long as that page was open.
Degorath 1mo ago
Thought I saw that announcement on LinkedIn a few weeks back already!
- steveklabnik 1mo ago
  Yes, he joined a few months ago, this is just getting it onto the site :)
mplewis 1mo ago
Can someone at ERSC please fix the issue preventing back/forward scroll gestures from working on the site?
- nickisnoble 1mo ago
  Filed a bug, looking into it! Edit: a fix is in review
fnord77 1mo ago
am I in some alternate timeline where ISVs are able to make a profit selling version control systems?
- steveklabnik 1mo ago
  We’ll find out!
- iota971 1mo ago
  New age of vendor lock-in?
schneems 1mo ago
Big news. Congrats.
- steveklabnik 1mo ago
  Thanks man :)
mturilin 1mo ago
At first I thought this post about martial arts…
umvi 1mo ago
I like the idea of jujutsu, but I must not operate at a scale where its "killer features" would truly shine. Git hardly ever gets in my way, I have never had to do complex octopus merges or anything like that. It's usually: feature branch, implement, merge, and occasionally fix a merge conflict. JJ seems like it's more for people that like to have tons of active branches that they are constantly switching between whereas I usually only work on 1 thing at a time. I've never thought to myself "git is so frustrating I wish there were something better" because I only use the same 5 commands over and over every day and they never get in my way. Not to mention jj has its own share of esoteric syntax with all the "@--+::" business and I'd have to re-wire my brain to remember those symbols instead of `ref~N`, etc.
- y1n0 1mo ago
  I was a skeptic until a few months ago. It’s my daily driver now. I’ve got sizable amount of people committing to the same repo, many are not skilled with git. So I deal with weird crazy “how did you ever get the repo into this state” issues not infrequently. JJ is just so low friction. The seamless and painless shuffling of commits, working up and down the commit chain without explicit rebasing, unchanging change-ids. The min identifiers in change-ids being highlighted. Being able to make commits and worry about the message later. Snapshots of changes while you are working serving as a tool agnostic undo. Painless and sensible cli args that are vastly more consistent than git. Superior conflict handling. You can “jj undo” anything and it works perfectly. It’s fabulous. > "@--+::" I have no idea what that means and I’ve never had to type anything remotely like it. The rev specification language is pretty elaborate but you don’t need to know it.
  - iota971 1mo ago
    [flagged]
    - MrDrMcCoy 1mo ago
      Maybe it's losing steam because it's stable and there's no demand for new features.
cisrockandroll 1mo ago
Badass!!! Congrats. I love JJ’s mental model. Its so much less opionated and lets me do what I want. Want to make 5 versions of the same commit? Easy. Need to push out a change asap without having to pre create a branch, stash your changes, yadayada. Jj just adapts. Once you start thinking in jj it becomes frustrating having think back to use GitHub as a code repo.
- vaylian 1mo ago
  > Want to make 5 versions of the same commit? Easy When do you need something like this?
  - cisrockandroll 1mo ago
    When I am not sure what direction I want to go in next, and so I try multiple versions from the same starting point.
clickety_clack 1mo ago
I tried jujutsu for a while and it’s nice if you’re the kind of person who lives in the commits. But it became a bit of a pain to manually move the branch name around all the time, and I spend a lot more time moving forward on a few branches than I do trying to figure out histories so I went back to git.
- stouset 1mo ago
  FWIW, most of the time I don’t even bother naming my branches. ‘jj git push -C` even handles naming for me when I want to make a PR, but that’s mostly the only time I bother. When I do need to advance a branch name, `jj bookmark advance` is easy enough. And it works great with the model that `jj git push` pushes all out-of-sync branches. In this model, advancing a bookmark is the reliable signal that I’m ready to share work, not simply “having authored a commit”.
cptmurphy 1mo ago
Can't live without JJ, but it does not scale yet: waiting sparse, blobless, treeless support
iota971 1mo ago
[dead]
- anonreplier 1mo ago
  Who says it's too complex to have multiple implementations? It's under an open source license notably unlike BitKeeper, what's the problem?
  - brilliantee 1mo ago
    Git had a very small initial implementation, while jj is under development for years and is large. If jj is not too complex to have multiple implementations, why have new implementations not sprung up by now? Is it the Google CLA, or are too few people using jj, or is jj too complex, or some mixture of all of the above? The Google CLA is still required as of 2026, which I find strange. https://lwn.net/Articles/958805/ https://lwn.net/Articles/958805/ > Second, I thought about contributing a fix to that table, and then I saw the contributing requirements: > > Contributor License Agreement > Nope, not happening. Nobody should adopt this until it's been freed from that requirement, either by getting the project to remove it or by establishing a version of the project that takes contributions without that requirement.
    - KingMob 1mo ago
      > why have new implementations not sprung up by now? Nobody wants to yet? FWIW, while there aren't multiple reimplementations of the core yet, there ARE multiple GUI and wrapper projects that fulfill various needs, if you're just looking for outside contribution as a health measure.
    - aseipp 1mo ago
      Jujutsu also started out very small, just like Git did. The core concepts aren't too complex. But this is 2026, not 2005 or 2019. Most of the modern Git implementations are extremely large, highly optimized and featureful codebases that are difficult to replicate. Many of Git's performance and structural improvements over the last few years have nontrivial implementations and designs. Jujutsu is also a large, featureful codebase. You can't build a modern Git implementation with all of the highly optimized goodies (multipack indicies, partial clones, etc) and a good UX without a lot of code and work. Or any version control system, frankly. It's just how it is. - Gitoxide is 80,000+ lines of code. - Git itself is over 170,000 lines of code. - Even "Game of Trees" or "got" by the OpenBSD developers, which is a wholly separate project that has its own porcelain, is +120,000 LOC. - Jujutsu itself is about 100,000 LOC. - JGit for Java is around 200,000 LOC. These are all roughly approximate and include things like testing code (but I think that's fair because tests are part of the project). All of these projects started small years ago, and are now large. > If jj is not too complex to have multiple implementations, why have new implementations not sprung up by now? "Make multiple implementations" is not, in and of itself, particularly valuable without some underlying justification to do so. It also is not how (AFAIK) any other version control system has ever worked; Git's "identity" as an on disk format is a particular design choice (with pros and cons), so yes you can get multiple tools with varying levels of features that agree on the basic disk format and poke at it. But most projects just don't work this way, much less other VCSs; there also aren't really many "Linux re-implementations" beyond toys because it is easier to just collectively contribute with each other, because Linux is not a "standard" written in stone, but a living and breathing thing.
Wren_ops 1mo ago
Hope ERSC is ready for their complex narrative structures. Jujutsu Kaisen's plot threads are mind-bending.
- nickisnoble 1mo ago
  We have a multi-season arc already planned, with at least 4 unannounced characters ⋆˚.⋆⋆˚.⋆
hitekker 1mo ago
Sounds like good news, with a great site UI. Particularly the slow moving background
syngrog66 1mo ago
[dead]
ashkankiani 1mo ago
I pretty much only use jj now, and it was really good even just with the CLI. But adding jjui changed the story entirely. I now rarely use jj without just booting up jjui first. It will be good to see what jj will look like with more funded dev work, but I'm always a little worried about financial incentives mixing with the tools I use for the long term. I guess the saving grace is that I don't really need more upgrades to jj or jjui as it stands. I'm pretty much content with the features and so I could just save this copy of the repo for future reference. As far as large assets goes, I have my own VCS-ish system which I just integrate with jj, but it would be nice to see a non-git backend handle large assets better as well.
- ku1ik 1mo ago
  Same here. I keep jjui open the whole day, rarely reaching for jj itself. It really changed the way I work with repos.
  - nchmy 1mo ago
    This is the way
janandonly 1mo ago
Why does OpenText (webshield) block this website?
- steveklabnik 1mo ago
  No clue, I’ve never heard of that. What does it tell you?
le-mark 1mo ago
> The company is building tools to help organizations manage the exponentially increasing needs Oh no! Looks like the ram shortage wasn’t enough, SSDs are next! /s
guytv 1mo ago
[flagged]
pjjpo 1mo ago
Funny how the threads are all about jj. Personally the move to a startup focused on version control, to me an obvious sinking ship, is more interesting. Not spectrum though.

265 points by steveklabnik 1mo ago

valvix 1mo ago

What a pivot, from manga to software

deleted 1mo ago
[deleted]

matthewbauer 1mo ago

Is this new? The date says July 8, 2026.

steveklabnik 1mo ago
Fixing, thank you! (Martin joined back then, but we are posting about it today, so we should have the post date as today)

steveklabnik 1mo ago

Working with Martin has been a real pleasure, and we'll have some more stuff to talk about very soon!

opem 1mo ago
excited for what you guys would be coming up with ;) btw, did Martin leave google?
- steveklabnik 1mo ago
  Thanks! Martin left Google for this, yes.
  - underdeserver 1mo ago
    Wasn't it partially owned by Google? Or are they just a contributer now?
    - steveklabnik 1mo ago
      I like to compare Google and jj to Mozilla and Rust: Google employed Martin and some other maintainers, but it's always been an OSS project under the Apache 2.0 license. That being said, there's a few things that lead to this perception: the first is that it used to be under Google's GitHub account, but is now under its own org. The second is that contributing to jj does require signing Google's CLA. That is something that is desired to change, but that's up to Google. Due to the license, the community could fork it, and still have the rights to use the code, but that would be pretty aggressive, and so everyone involved would rather work together on this than do so. The move to its own GitHub org was one example of movement in that direction, but I'm not aware of an actual timeline to remove the CLA just yet. The project will figure it out over time. (I have a commit bit but am not a jj maintainer, so the above is my own impression from being involved in the community for the past few years.)
      - underdeserver 1mo ago
        Thanks! Maybe if Martin could comment - his @google.com email still appears in the repo readme, I'm assuming he doesn't have access to that box anymore - was the repo move and ownership coordinated with Google prior to his leaving?
        martinvonz 1mo ago
        The move from martinvonz/jj to jj-vcs/jj happened almost two years ago. https://github.com/jj-vcs/jj/commit/b836e0ae9518154cd52f94e045bfe808b4471f1a https://github.com/jj-vcs/jj/commit/b836e0ae9518154cd52f94e0... (from 2024-12-17) says that it was recent at that time. Google were owners even when it was under martinvonz/jj, however.
      - mcookly 1mo ago
tcoff91 1mo ago
I absolutely love jj (just check my HN comment history). One thing I'd love to see in jj though that git does better is copy tracking. If somebody renames a file upstream, and you go to rebase your commit that touches that file onto main, jj doesn't handle this very well compared to git. Do you have any idea if this is coming to jj soon?
- steveklabnik 1mo ago
  There is active work in this area, yes! https://github.com/jj-vcs/jj/issues/3386 https://github.com/jj-vcs/jj/issues/3386 is the bug tracking the feature request, and there have been some recent PRs working on implementing this, see here for one example: https://github.com/jj-vcs/jj/pull/9864 https://github.com/jj-vcs/jj/pull/9864
- drsouth 1mo ago
  Do you happen to have or know of any good open source projects on any public platform like GitHub, gitlab or Codeberg, that uses Jujutsu/jj?
  - nickisnoble 1mo ago
    It's hard to tell since any given dev can just use jj locally, if they want to, while everyone else uses git.
    - dzaima 1mo ago
      Technically, you can still tell actually - jj writes a "change-id xyz..." in the git commit object header, which remains there as it's pushed around. It's just typically not made visible by regular things. (I wonder what other random garbage has been hidden in git commit headers that noone has seen)
      - OJFord 1mo ago
        Huh, fortunate for it that GitHub (especially) preserves it then! I wonder how guaranteed that is, can imagine GH deciding to 'clean' it (how much data can you put there theoretically? Or to close a range of potential security issues) and suddenly relatively niche but genuine uses like jj's change-id are unintentionally not preserved.
drsouth 1mo ago
Will this have any chance if Jujutsu/jj doesn't get more traction? The effort to learn a new VCS is less than for a programming language, but many developers have not learned git in depth, and Mercurial and others have not gained a lot of traction.
- Kinrany 1mo ago
  It doesn't require that everyone switch at the same time, unlike other VCSs.
- saghm 1mo ago
  I'd argue that the reason a lot of developers have not learned git in depth is because it's actually kind of terrible from a UX standpoint (lots of inconsistent naming of things and somewhat leaky abstractions), and that Mercurial faced an uphill battle in large part because it lacked compatibility with what people were already using. I haven't used Mercurial, but from what I've heard quite a lot of how jj does things is similar to Mercurial, just in a way that's compatible with git. I haven't used git directly for over a year in favor of using jj despite exclusively using git repositories, and no one I've worked with has even needed to be aware.
  - skydhash 1mo ago
    > I'd argue that the reason a lot of developers have not learned git in depth is because it's actually kind of terrible from a UX standpoint Not really. I remember my early years with git and the favt was that I never needed more than clone, add, commit, pull and push. While I’ve done some mistakes that got ne to learn more, especially with creating branches and undoing. I’ve never needed a lot, even when I started using GUI which exposed more concepts. Why? Because I have no understanding of version management and how it’s useful in a dev workflow/release process. I was just using it for checking in work. Since then, I’ve read the “Pro Git” book, learned how devs and teams handle versioning and devel a good understanding of how git can help me in my coding process and general software development. And it’s very good at what it does.
    - 1mo ago

tensegrist 1mo ago

what a lovely website

steveklabnik 1mo ago
Thank you! We liked our old look, but one funny thing about how things are going in the world: our old color scheme was too close to what happens when you ask Claude to generate a site, and so even though we paid a human to build it, we didn't want to communicate slop, especially because that's not what we did! Nick Noble is our designer, he put in a bunch of work on this, and I really like it too.
- poly2it 1mo ago
  I love how little latency there is on your website. I'm often thrown off by websites freezing on navigation, something we euphemistically call "loading". I feel we should have moved beyond that in the year of 2026. Your website really respects the user in this regard. Aesthetics are splendid as well.
- figbert 1mo ago
  Nick is great! Met him at the Recurse Center. Brilliant designer.
  - nickisnoble 1mo ago
    :octopus:!
nickisnoble 1mo ago
Thanks! There will be a lot more of it soon :D
- spankibalt 1mo ago
  Hire somebody who's got at least a modicum of understanding of (web) typography. Small hint: A moving background layer makes reading supremely annoying, and for some people even (virtually) impossible.

RobotToaster 1mo ago

Jujutsu is apparently the name of a version control system, for anyone else confused how the creator of a thousand year old martial art had joined them.

CobrastanJorji 1mo ago
Thanks, I was trying to work it out in my head. I knew brazilian jiu jitsu was 20th century, and I was like "but wait, is jiu jitsu itself not that much older, that seems very surprising."
- zerr 1mo ago
  Yeah. I thought maybe someone from Gracie family joined something :)

infogulch 1mo ago

What is ERSC?

steveklabnik 1mo ago
I wrote a bit about this here: https://news.ycombinator.com/item?id=49526190 https://news.ycombinator.com/item?id=49526190 I wrote about why I joined the company back when I did previously here: https://steveklabnik.com/writing/i-see-a-future-in-jj/ https://steveklabnik.com/writing/i-see-a-future-in-jj/ In short: we are building a next generation source control system for the enterprise.

fallat 1mo ago

Someone will have to explain the value proposition to me... We have git. jujutsu works with git. git can do everything jujutsu can do (otherwise, jujutsu couldn't work with git). Thus, jujutsu is a UX / new steering wheel. ERSC is trying to be a GitHub competitor with what surplus value? Don't get me wrong, GitHub has a slew of its own problems, but I have not seen any commentary on how ERSC addresses any of the downfalls GitHub has too. We're jumping from one frying pan into another, currently-cooler one? What about SourceHut? Codeberg? They could offer the same steering wheels. Edit: Thank you to everyone who replied. The enterprise/teams infrastructure angle makes sense.

rirze 1mo ago
I might be mistaken, but I always figured the end goal for jujitsu was to use its own backend. Supporting git-colocation seems like a compatibility case to bring users over. If I had to guess, then I would say ERSC is trying to build a `jj` forge based on this new hire and that would be amazing imo.
- zmodem 1mo ago
  Maybe like some kind of https://jjhub.com https://jjhub.com :-)
steveklabnik 1mo ago
We'll be saying more about this very soon, but the short version is this: we are not building a GitHub competitor in the way that SourceHut or Codeberg are. We are building infrastructure for enterprises, not a social coding site. While jj works with git, it doesn't have to. jj has the ability to work with many backends. Git is the popular one in the open source world, but that doesn't mean that other ones are not possible. And that's the core tech we have built. With the rise of agents, more and more companies are running into the limits of what Git can do. It was never designed for large monorepos, and so there are performance issues, but also features that it's missing, that are important once you start trying to scale things up to an entire organization. Companies like Meta and Google ran into these things well before the present moment, but you don't have to be a FAANG these days to be running into this sort of stuff. We also understand that incremental adoption is really important, especially for something as fundamental as source control. So our tech also has a git ingress/egress that will work with the core functionality, but more advanced things that git simply can't do will end up requiring using a non-git protocol. jj is the bridge between those two worlds. I hope that makes sense! We have been in psudeo-stealth for a while now, this is the start of us coming out of our shell a bit and actually talking about what we're doing.

jph 1mo ago

Jujutsu is a better smarter git. It's a great convergence of better UX, plus more expressive, plus easier to use. If you haven't tried jj yet, take it for a spin and see how you like it.

drsouth 1mo ago
How does it compare to Mercurial? And why would it get more traction than Mercurial?
- yegle 1mo ago
  Mercurial is too slow. Even with chg common commands like `hg status` may take hundreds of milliseconds. JJ is fast. Internally `jj log` taking more than 500ms is tracked as bugs.
  - drsouth 1mo ago
    [dead]
    - yegle 1mo ago
      Well I did not answer your second part of the question, only the first part of comparing Mercurial vs Git. Now to the second part: I think speed still plays a role back when Bitbucket and Google Code provides Mercurial hosting and people were comparing Mercurial with Git. Eventually GitHub won the competition, so then we kinda stuck with Git.
- Arainach 1mo ago
  Git already won through Github, the Linux kernel, and other important projects. Even if you like Mercurial's syntax better (I do) and wish it won (I do), that battle was over many years ago. jj's data store is git. You can use jj while other people on your project just use git. There's no migration of data or history. You can use Github and all of the various git tooling that exists today. As such, the initial cost of switching to jj is zero for individuals, teams, or projects. That's huge. jj's ergonomics are significantly nicer. Fewer ways to shoot yourself in the foot, much better merge resolution, etc.

drcongo 1mo ago

This looks like excellent news.

medicalux 1mo ago

[flagged]

swiftcoder 1mo ago
Man, sockpuppet accounts on every rust-adjacent story on here are beyond tiresome. What does someone actually get out of being anti-rust?
- fakoosu 1mo ago
  [flagged]

fenugurod 1mo ago

That’s amazing news. Can you share more about your tech stack? I suppose it’s mainly built with Rust?

steveklabnik 1mo ago
We have a colopholon! https://ersc.io/colophon https://ersc.io/colophon Rust is the default language for all of our non-frontend web stuff, yes.

ksymph 1mo ago

So if I understand correctly: ERSC is working on an alternative backend for jj other than git (and presumably providing related infrastructure)?

yegle 1mo ago
I think it's closer to: develop something similar to Google's Piper as (hopefully!) an open source project and sell this to enterprise, similar to Perforce's business model but with the benefit of an excellent and well received frontend tool.

KajMagnus 1mo ago

Congrats (or what's the right word :- )) Martin and best wishes to you and ERSC, Looking forward to using the VCS stuff you'll create :- )

waldrews 1mo ago

(off topic) why the headache-inducing animated background? An annoyance for all, and an actual accessibility issue for some.

steveklabnik 1mo ago
Not off topic! We should be respecting https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules/@media/prefers-reduced-motion https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/A... . If we do not, that's a bug, and please let me know what browser/OS/whatever else combo you have if that is an issue.
- tefkah 1mo ago
  seems to respect reduce motion just fine! the animation, while extremely lovely, also does seem to be quite taxing on my GPU (~60% usage on M1 Max with Zen/Firefox, on a 1440p widescreen, which is admittedly quite a lot of space to render animation) love the website though, i hope i one day will be able to make something that elegant!

minraws 1mo ago

jj is one of the few new devtools I was quite frustrated with while starting out but could see the value so stuck around and man is it so nice. For anyone curious the big thing with jj is you can undo. Basically if you were running a rebase and bungled a commit sha or branch name, no worries undo your way out, if you forgot to push but abandoned a commit not issues undo it. Same with all jj commands. Delta db takes this a step further and everything you edit is a change so your actual edits are also all saved. I find non destructive-ness for as long as possible approach very nice, since there aren't as many constraints on us not being able to do it nowadays, we had limited storage and stuff in 2000s perhaps but in 2026 even with the killer SSD prices it's fairly cheap to buy more SSD, we can definitely waste 100MB per project storing redundant history we may not ever need. Same way in photoshop non destructive editing took over, especially useful for humans, but works for AI and LLMs too, they can undo their mistakes as well.

sshine 1mo ago
Are you saying push + undo = unpush?
- yegle 1mo ago
  AFAIKT it will revert the local state to "pending push".
- kps 1mo ago
  jj itself doesn't have a native ‘push’. `jj git push` and `jj piper upload`¹ operate on external systems that don't necessarily support undoing arbitrary operations. Pure speculation, but if I were ESRC I'd make my backend handle it (subject to enterprise audit policies). ¹ https://drive.google.com/file/d/1dVzug1lHoOxdbFu8gcCJCu-G_uVMUATI https://drive.google.com/file/d/1dVzug1lHoOxdbFu8gcCJCu-G_uV...
  - sshine 1mo ago
    Reminds me of the git-svn bridge. Points of no return.
- 1mo ago

fakoosu 1mo ago

[flagged]

sshine 1mo ago
Without having tried JJ, as a hype chaser, I can say it's both worth it and not worth it. I run NixOS, work with Kubernetes, code Rust, use a 40% split, layered keyboard with Dvorak layout and open source firmware, kaj mi parolas Esperanton. They're just hobbies that, once you've sunk the hours in, they're awesome. I don't actually type faster. Or maybe I do type a little faster because it made me use all 12 fingers instead of the ad-hoc 7-finger system you taught yourself in primary school, but typing was never a bottleneck, and split keyboards actually hurt my wrists more. Jujutsu is marginally better than git, but costs time. If you like to spend the time, it will probably make you a little better. If you care deeply about your time, and it's already being allocated for anything but arbitrary intellectual pursuit, it's not worth it. Some people grow businesses, plants, or sedentary habits.
skipants 1mo ago
the person you responded to has been a user since 2019. why do you think they artificially push it? I also use jj as my daily driver now. I like it a lot. I have no skin in the game either.

phi-go 1mo ago

No word about the future of Jujutsu, so I guess this is bad news for for jj users?

mtlynch 1mo ago
Isn't ERSC aiming to be for jj what GitHub was for git? In which case, this would be great news for jj.
steveklabnik 1mo ago
It's in the post, but Martin will be continuing to work on jj itself as well as on our products, just as he did at Google, working on the open source jj but also their internal source control team. As a side note, jj has rules around company representation in maintainership, and so when this initially happened a few months back, ERSC actually became over-represented in the maintainers group, as we also employ several other maintainers. The project decided to add more maintainers to keep the balance, rather than ask folks to step down. We very much want to properly support the upstream project, and we want to make sure that it continues to be awesome for everyone, not just our customers.
- sundarurfriend 1mo ago
  That idea about keeping maintainer balance is pretty neat, interesting to see this kind of diligence in maintainership in the same project where legal ownership belongs to a single company, Google, via the Contributor License Agreement. My interest in jj cooled off a lot after seeing that, even though I realize in practice it's pretty unlikely to be of consequence - I just don't need even that kind of low probability Sword of Damocles hanging over my VCS, forks and drama in case Google decides to mess things up. (Good to see that the Readme has been changed to say it's not a Google-supported project btw, less misleading than the old claim that it's not a Google project at all.)
  - steveklabnik 1mo ago
    Legal ownership does not belong to a single company. All copyrights are still held by each individual contributor, and they're available to be used under the Apache 2 license. The CLA means Google also has a license to the code to do what they will with it, but it does not do copyright assignment. They do not own your contributions.

mhd 1mo ago

"human ↔ machine collaboration" sounds rather creepy, to be honest.

keeganpoppen 1mo ago
tell that to Doug Englebart or J.C.R. Licklider-- the idea of human-computer symbiosis predates basically all computers that we would recognize as such today. crazy how it is only really now becoming true in the way that they envisaged in the 1960s.

drsouth 1mo ago

[flagged]

steveklabnik 1mo ago
I left a lengthy comment below about how we'll be supporting git as well. I have been a member of this community for a very long time. Posting here is something I just do. jj is already pretty well known here, there's articles about it quite often. But sure, I don't think that anyone would deny that a VC backed startup posting about their product to Hacker News has marketing value. You have to get the word out somehow. EDIT: oh, this person edited their comment after I replied. There's been a rash of these comments making wild, baseless accusations about Rust developers, thank you dang and the other mods for handling it.
- junon 1mo ago
  I've met you (Steve) and hung out with him for a few hours after oxidize. He's none of those things, and in fact was one of the most pleasant people I've met at conferences. So not only are they brazen and vulgar allegations but I can't see even a distant parallel universe where they're even close to true. Super bizarre comment to see on HN.

tolerance 1mo ago

I'm way more interested in knowing what technologies Steve Klabnik is eyeing and planning to get involved with next.

steveklabnik 1mo ago
I joined ERSC ten months ago! The things I am most interested in right now are jj and llms. And the intersection between the two. I'm thinking a lot these days about how agentic development is changing our industry, with source control being one part of that.

nh2 1mo ago

This website has unbearable scroll performance on mobile. Is it the animation at the top?

steveklabnik 1mo ago
We tested it in mobile, but several people pointed out that we have more performance work to do to make sure that the animation is fast on lower-end hardware. I don't know what phone you're using, but we'll get it fixed regardless.
- coffeeindex 1mo ago
  1 more data point - it's very slow on my desktop which has relatively high performance as well. Using Brave if that matters.
  - nickisnoble 1mo ago
    We're about to push a change that should improve this a bit, thanks for the reports!
    - nh2 1mo ago
      Thanks, the animation is gone now and the problems are gone as well. Good choice in my opinion, as I hadn't even noticed the animation existed until I looked for something that might make the scrolling slow.
- usefulcat 1mo ago
  One more data point--I'm using Firefox on an M1 Mac mini (MacOS 15.7.7), and this web site destroys the responsiveness of this system in a way I have literally never seen before (4+ years) from anything, web site or otherwise. I opened up Activity Monitor and CPU use looked normal but it showed the GPU was pegged at 100% as long as that page was open.

Degorath 1mo ago

Thought I saw that announcement on LinkedIn a few weeks back already!

steveklabnik 1mo ago
Yes, he joined a few months ago, this is just getting it onto the site :)

mplewis 1mo ago

Can someone at ERSC please fix the issue preventing back/forward scroll gestures from working on the site?

nickisnoble 1mo ago
Filed a bug, looking into it! Edit: a fix is in review

fnord77 1mo ago

am I in some alternate timeline where ISVs are able to make a profit selling version control systems?

steveklabnik 1mo ago
We’ll find out!
iota971 1mo ago
New age of vendor lock-in?

schneems 1mo ago

Big news. Congrats.

steveklabnik 1mo ago
Thanks man :)

mturilin 1mo ago

At first I thought this post about martial arts…

umvi 1mo ago

I like the idea of jujutsu, but I must not operate at a scale where its "killer features" would truly shine. Git hardly ever gets in my way, I have never had to do complex octopus merges or anything like that. It's usually: feature branch, implement, merge, and occasionally fix a merge conflict. JJ seems like it's more for people that like to have tons of active branches that they are constantly switching between whereas I usually only work on 1 thing at a time. I've never thought to myself "git is so frustrating I wish there were something better" because I only use the same 5 commands over and over every day and they never get in my way. Not to mention jj has its own share of esoteric syntax with all the "@--+::" business and I'd have to re-wire my brain to remember those symbols instead of `ref~N`, etc.

y1n0 1mo ago
I was a skeptic until a few months ago. It’s my daily driver now. I’ve got sizable amount of people committing to the same repo, many are not skilled with git. So I deal with weird crazy “how did you ever get the repo into this state” issues not infrequently. JJ is just so low friction. The seamless and painless shuffling of commits, working up and down the commit chain without explicit rebasing, unchanging change-ids. The min identifiers in change-ids being highlighted. Being able to make commits and worry about the message later. Snapshots of changes while you are working serving as a tool agnostic undo. Painless and sensible cli args that are vastly more consistent than git. Superior conflict handling. You can “jj undo” anything and it works perfectly. It’s fabulous. > "@--+::" I have no idea what that means and I’ve never had to type anything remotely like it. The rev specification language is pretty elaborate but you don’t need to know it.
- iota971 1mo ago
  [flagged]
  - MrDrMcCoy 1mo ago
    Maybe it's losing steam because it's stable and there's no demand for new features.

cisrockandroll 1mo ago

Badass!!! Congrats. I love JJ’s mental model. Its so much less opionated and lets me do what I want. Want to make 5 versions of the same commit? Easy. Need to push out a change asap without having to pre create a branch, stash your changes, yadayada. Jj just adapts. Once you start thinking in jj it becomes frustrating having think back to use GitHub as a code repo.

vaylian 1mo ago
> Want to make 5 versions of the same commit? Easy When do you need something like this?
- cisrockandroll 1mo ago
  When I am not sure what direction I want to go in next, and so I try multiple versions from the same starting point.

clickety_clack 1mo ago

I tried jujutsu for a while and it’s nice if you’re the kind of person who lives in the commits. But it became a bit of a pain to manually move the branch name around all the time, and I spend a lot more time moving forward on a few branches than I do trying to figure out histories so I went back to git.

stouset 1mo ago
FWIW, most of the time I don’t even bother naming my branches. ‘jj git push -C` even handles naming for me when I want to make a PR, but that’s mostly the only time I bother. When I do need to advance a branch name, `jj bookmark advance` is easy enough. And it works great with the model that `jj git push` pushes all out-of-sync branches. In this model, advancing a bookmark is the reliable signal that I’m ready to share work, not simply “having authored a commit”.

cptmurphy 1mo ago

Can't live without JJ, but it does not scale yet: waiting sparse, blobless, treeless support

iota971 1mo ago

[dead]

anonreplier 1mo ago
Who says it's too complex to have multiple implementations? It's under an open source license notably unlike BitKeeper, what's the problem?
- brilliantee 1mo ago
  Git had a very small initial implementation, while jj is under development for years and is large. If jj is not too complex to have multiple implementations, why have new implementations not sprung up by now? Is it the Google CLA, or are too few people using jj, or is jj too complex, or some mixture of all of the above? The Google CLA is still required as of 2026, which I find strange. https://lwn.net/Articles/958805/ https://lwn.net/Articles/958805/ > Second, I thought about contributing a fix to that table, and then I saw the contributing requirements: > > Contributor License Agreement > Nope, not happening. Nobody should adopt this until it's been freed from that requirement, either by getting the project to remove it or by establishing a version of the project that takes contributions without that requirement.
  - KingMob 1mo ago
    > why have new implementations not sprung up by now? Nobody wants to yet? FWIW, while there aren't multiple reimplementations of the core yet, there ARE multiple GUI and wrapper projects that fulfill various needs, if you're just looking for outside contribution as a health measure.
  - aseipp 1mo ago
    Jujutsu also started out very small, just like Git did. The core concepts aren't too complex. But this is 2026, not 2005 or 2019. Most of the modern Git implementations are extremely large, highly optimized and featureful codebases that are difficult to replicate. Many of Git's performance and structural improvements over the last few years have nontrivial implementations and designs. Jujutsu is also a large, featureful codebase. You can't build a modern Git implementation with all of the highly optimized goodies (multipack indicies, partial clones, etc) and a good UX without a lot of code and work. Or any version control system, frankly. It's just how it is. - Gitoxide is 80,000+ lines of code. - Git itself is over 170,000 lines of code. - Even "Game of Trees" or "got" by the OpenBSD developers, which is a wholly separate project that has its own porcelain, is +120,000 LOC. - Jujutsu itself is about 100,000 LOC. - JGit for Java is around 200,000 LOC. These are all roughly approximate and include things like testing code (but I think that's fair because tests are part of the project). All of these projects started small years ago, and are now large. > If jj is not too complex to have multiple implementations, why have new implementations not sprung up by now? "Make multiple implementations" is not, in and of itself, particularly valuable without some underlying justification to do so. It also is not how (AFAIK) any other version control system has ever worked; Git's "identity" as an on disk format is a particular design choice (with pros and cons), so yes you can get multiple tools with varying levels of features that agree on the basic disk format and poke at it. But most projects just don't work this way, much less other VCSs; there also aren't really many "Linux re-implementations" beyond toys because it is easier to just collectively contribute with each other, because Linux is not a "standard" written in stone, but a living and breathing thing.

Wren_ops 1mo ago

Hope ERSC is ready for their complex narrative structures. Jujutsu Kaisen's plot threads are mind-bending.

nickisnoble 1mo ago
We have a multi-season arc already planned, with at least 4 unannounced characters ⋆˚.⋆⋆˚.⋆

hitekker 1mo ago

Sounds like good news, with a great site UI. Particularly the slow moving background

syngrog66 1mo ago

[dead]

ashkankiani 1mo ago

I pretty much only use jj now, and it was really good even just with the CLI. But adding jjui changed the story entirely. I now rarely use jj without just booting up jjui first. It will be good to see what jj will look like with more funded dev work, but I'm always a little worried about financial incentives mixing with the tools I use for the long term. I guess the saving grace is that I don't really need more upgrades to jj or jjui as it stands. I'm pretty much content with the features and so I could just save this copy of the repo for future reference. As far as large assets goes, I have my own VCS-ish system which I just integrate with jj, but it would be nice to see a non-git backend handle large assets better as well.

ku1ik 1mo ago
Same here. I keep jjui open the whole day, rarely reaching for jj itself. It really changed the way I work with repos.
- nchmy 1mo ago
  This is the way

janandonly 1mo ago

Why does OpenText (webshield) block this website?

steveklabnik 1mo ago
No clue, I’ve never heard of that. What does it tell you?

le-mark 1mo ago

> The company is building tools to help organizations manage the exponentially increasing needs Oh no! Looks like the ram shortage wasn’t enough, SSDs are next! /s

guytv 1mo ago

[flagged]

pjjpo 1mo ago

Funny how the threads are all about jj. Personally the move to a startup focused on version control, to me an obvious sinking ship, is more interesting. Not spectrum though.