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Mojo is now open source
- Lichtso 2mo agoTechnically soruce available now with the promise of accepting contributions (thus becoming fully open source) early next year. But since it is an Apache 2 license (like the rest of the LLVM project) you are already allowed to fork and contribute to your own fork right now, just no upstreaming. For many the closed source nature of the compiler was a knock-out criterion. We will see if Mojo can gain traction now or if it has missed its window of opportunity.
- fluffybucktsnek 2mo agoTechnically, the criteria for open source is freedom to freely distribute and modify the source code, not to upstream changes. That's a different for thing. https://opensource.org/osd https://opensource.org/osd
- cube2222 2mo agoIt’s open source under the Apache 2 license, not source available. Accepting contributions is not required to be open source. SQLite doesn’t accept contributions from random people either [0] (though you could argue being public domain isn’t being open source). Anyway, this is great, I was waiting for this to take the language for a spin! Congrats to the Mojo team! [0]: https://simonwillison.net/2025/Dec/29/copyright-release/ https://simonwillison.net/2025/Dec/29/copyright-release/
- roundabout-host 2mo agoMaybe it is not listed by the OSI, but it is 'open source' in practice, if the source is also in the public domain. The FSF's definition of free software makes more sense not only ideologically, but also because it does not try to be exhaustive.
- lukaslalinsky 2mo agoOne problem is that a large part of Europe doesn't understand the concept of public domain. I'm not legally allowed to not own my creation, except by transferring it to someone else. That's why licences like CC0 exist.
- SwellJoe 2mo agoYou're just making up your own definitions of things. If the complete source is available and distributable under an OSI-approved license, it is absolutely Open Source. Accepting outside contributions is nowhere in the definition of Open Source.
- zephen 2mo agoIt seems like the same sort of category error that some people make regarding free speech. Just as you can say whatever you want, but facebook/twitter/reddit/whoever is not required to give you a soapbox, you can download this software and make whatever changes you want, but nobody is required to give a shit about your proposed changes.
- totalperspectiv 2mo agoThis is really exciting. I've been using Mojo off and on for side projects over the last two years. (copying from some previous Mojo threads) It's got an ownership system adjacent to Rust, comptime similar to Zig, and a first class dependent type system. Even more exciting, is that uses LLVM (to the best of my understanding) in some novel ways and for more optimizations.
- dlahoda 2mo agoHm, in docs they say that dependent type system is not first class seems. Is it even dependent? More like refinement types, which seems will be in Rust too.Also HN recently mentioned Rust building similar llvm based integration with GPU. But compared with Python, Julia, Matlab, R, Rust, C, C++ - Mojo feel relief for working with numerics.
- Archit3ch 2mo ago> But compared with Python, Julia, Matlab, R, Rust, C, C++ - Mojo feel relief for working with numerics. Out of those, Julia is the only one that combines Multiple Dispatch and native code, both important for numerics.
- jondea 2mo agoI don't agree at all with your last paragraph. MATLAB and Julia are lovely for numerics, maths is terse and looks like maths! Mojo is hobbled by choosing Python style syntax, which does not lend itself well to maths. WRT the type system, I agree MATLAB is a mess but Julia's multiple dispatch feels more like maths than any other language I've tried.
- melodyogonna 2mo agoRelated post with relevant pr: https://news.ycombinator.com/item?id=49347777 https://news.ycombinator.com/item?id=49347777
- ChrisArchitect 2mo agoRelated: Mojo 1.0 https://news.ycombinator.com/item?id=49261128 https://news.ycombinator.com/item?id=49261128
- melodyogonna 2mo agoSuch an exciting time for Mojo, I don't think people realize just yet the innovation being brought to fore here.
- vovavili 2mo agoThe innovative potential of Mojo would be constrained to relatively niche and senior dev circles until they get a Windows release, which probably won't happen anytime soon. Python keeps the throne for now.
- dloss 2mo agoThey announced a partnership with Microsoft today.
- vovavili 2mo agoThat's quite promising - https://www.modular.com/blog/modcon-announcements#:~:text=Windows%20support%20for%20Mojo https://www.modular.com/blog/modcon-announcements#:~:text=Wi...
- pjmlp 2mo agoAnd Julia as well.
- rirze 2mo agoIt's a sad time to be a fan of Julia-- everyone forgets it's there.
- archargelod 2mo agoI was excited to try Julia, but then, as I saw it was an interpreted language, with bulky runtime, slow startup times and bloated library sizes - my initial interest quickly faded. For the same reasons I see languages like Python, Java, C# as inferior.
- setopt 2mo agoVery exciting. Closed source was one of the main things making me not try it out yet. Any good resources for getting started? And anything on doing NumPy/SciPy-like stuff in it?
- MohamedMabrouk 2mo agoNuMojo is the closest thing in the ecosystem to numpy and the final aim is offer numpy-like experience. https://github.com/Mojo-Numerics-and-Algorithms-group/NuMojo https://github.com/Mojo-Numerics-and-Algorithms-group/NuMojo
- vovavili 2mo agoCan't you just use Numpy directly in Mojo?
- MohamedMabrouk 2mo agoyou can but through a python interpreter in the mojo process so you get the same numpy speed with mojo<->ptyhon interop overhead. NuMojo is native and also is now starting to support features that numpy can't really do like native GPU execution.
- vovavili 2mo agoI wonder if the Python-to-Mojo overhead is significant enough where language-native bindings make more sense. I'd be interested in seeing some benchmarks.
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- ch4s3 2mo ago> numpy can't really do like native GPU execution I'd be interested to see where GPU code beats NUMPY's SIMD implementation, which is really
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- mrbonner 2mo agoSo I think the permissive license like Apache 2 without opening up for upstream contributions would be the way of future open source development. In a very similar way of SQLite. It definitely will help shield off a bunch of AI generated contributions first and foremost and then, aligning mental model with the human contributions with Mojo leader team.
- SwellJoe 2mo agoAs long as it was proprietary, I could ignore it. Now, I guess I have to learn a little something about it.
- ModernMech 2mo ago"Modular Confidential (obviously), May 14, 2022" lol, feels like espionage https://github.com/modular/modular/blob/main/KGEN/docs/DesignOverview.md https://github.com/modular/modular/blob/main/KGEN/docs/Desig... Compiler walkthrough https://github.com/modular/modular/blob/main/KGEN/docs/MojoCompilerWalkthrough.md https://github.com/modular/modular/blob/main/KGEN/docs/MojoC...
- melodyogonna 2mo agoOne of my favourite features of Mojo is linear types and how deeply they have been integrated into manual memory management - see:https://x.com/melodyogonna/status/2085089269484343725?s=20 https://x.com/melodyogonna/status/2085089269484343725?s=20. When I first learned about linear types, my first thought of the use case was making manual allocations and deallocations safer without sacrificing usability, but I didn't know what that could look like; now I do. This is great because in Mojo, pointers are surfaced a lot more than in, say, Rust, but such sharp tooling in a language you expect to be safe by default can be problematic. Linear types, combined with the origin system, give the language a lot of flexibility; it is like using a sharp tool with a safety glove: the tool isn't any less sharp, but the chances of accidentally injuring yourself are reduced.
- phplovesong 2mo agoHow does mojos linear types work in a concurrent environment?
- melodyogonna 2mo agoMojo's concurrency model is yet to be figured out.
- branko_d 2mo agoIs this a case of of Qualcomm commoditizing their complements? Does Mojo have a potential for disrupting Nvidia's current market position? https://www.joelonsoftware.com/2002/06/12/strategy-letter-v/ https://www.joelonsoftware.com/2002/06/12/strategy-letter-v/
- melodyogonna 2mo agoI think people underestimate the fact that Nvidia's GPUs are really good. Modular/Qualcomm's stack will provide a lot more optionality, but from what I saw in the Modcon conference on Tuesday, most of the target audience is towards other hardware vendors. At the moment, after designing a new hardware, you'd have to also build the entire software stack already existing on Cuda, ROCm, etc - this can double or triple your hardware bring up time. If you plug into Max (not Mojo), you get most of the software stack for free, so your software bring up time can go from months of engineering hours to probably weeks.
- adastra22 2mo agoFor AI? GPUs actually kinda suck. NVIDIA’s GPUs are best, and their software stack is great, but they aren’t really adapted to AI (training or inference).
- melodyogonna 2mo agoI wouldn't say they suck, but they're general-purpose. Anyway, you've gotten into the core of what makes Modular's stack useful. GPUs are great, but it has become obvious that they leave performance on the table, so dedicated AI accelerators get built; however, these don't have software infrastructure and kernels that have been tuned and optimised for years, like CUDA. The bet here is that you can build great hardware, and with a little bit of effort you can unlock all the necessary software for your hardware.
- adastra22 2mo agoEven general purpose matrix multipliers built for large linear systems instead of 3D graphics would get you orders of magnitude improvement. That’s essential what the current generation of AI accelerators are. Dedicated hardware could improve that further. I think that counts as “kinda sucks” in the absolute sense. It’s just far faster and more efficient than any other thing you can buy off the shelf today.
- andsoitis 2mo agoLove this intentionality: ” Our open source approach has been deliberate: we’ve found that small and tight-knit design teams (not committees) are the best for finding the “soul” of a language, but that feedback from a broader community is essential to escape an echo chamber. As such, we first open-sourced the Mojo standard library, then released hundreds of thousands of lines of kernel code written in Mojo, tools, and support. We built together with community feedback and public design proposals, and are now open sourcing the compiler. We will continue to open our processes further as Mojo keeps maturing.”
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- giancarlostoro 2mo agoI wish they never abandoned the goal of being a true Python superset. That would have been something.
- JBits 2mo agoI don't think the goal of being a true Python superset ever existed. Given that there are so many failed attempts to optimise arbitrary Python code, it was dubious from the start. Furthermore, the documentation completely ignored these challenges and made it clear that Mojo's goal was to compile to MLIR in order to write kernels for machine learning. The first example of Mojo code was a low level matrix multiplication kernel taking advantage of fancy compilation features and the documentation advertised pointers inspired by Rust's move semantics, neither of which are typically considered friendly or relevant to high level programmers.
- giancarlostoro 2mo agoIt was in their roadmap: https://forum.modular.com/t/mojo-as-a-python-superset/2490 https://forum.modular.com/t/mojo-as-a-python-superset/2490
- 2mo ago
- dang 2mo agoRecent and related: Mojo 1.0 - https://news.ycombinator.com/item?id=49261128 https://news.ycombinator.com/item?id=49261128 - Aug 2026 (244 comments)
- WalterGR 2mo agoFrom yesterday: The Mojo language (by Modular, now Qualcomm) is now open-source - https://news.ycombinator.com/item?id=49358327 https://news.ycombinator.com/item?id=49358327 - 108 comments
- pmkary 2mo agoWhat a beautiful standard library btw. Much to learn and take from.
- Alien1Being 2mo ago"Qualcomm to Acquire Modular 06/24/2026" https://investor.qualcomm.com/news-events/press-releases/news-details/2026/Qualcomm-to-Acquire-Modular/default.aspx https://investor.qualcomm.com/news-events/press-releases/new... Can acqui-death be far away...?
- ipsum2 2mo agoPrediction: Chris Lattner will be off chasing some other shiny thing within a year. Without a strong champion, the company will be subsumed into Qualcomm and stop publishing meaningful updates.
- blltprfmnk 2mo ago100% on both counts but don't know if it's "within a year", or within a couple.
- chrismsimpson 2mo agoI have this pang too, but for a different reason: everything is moving to the edge, training and inference. Who needs a complicated heterogeneous setup like this when you’re running everything locally?
- melodyogonna 2mo agoChris Lattner is now Qualcomm's VP of AI Software and Tooling, so he is now responsible for all of Qualcomms AI software. Mojo wouldn't be doing any dying
- fancyfredbot 2mo agoChris Lattner is now very very rich. Once his lockup expires he will not need to work for anyone. I'm sure Qualcomm would love him to stick around but suspect that they'll maintain mojo even if he leaves.
- bernaferrari 2mo ago
- eatonphil 2mo agoI did a review of Mojo a few months ago focused on Python compatibility if anyone's curious about that angle. Admittedly it is a narrow angle. I want to take another look at Mojo sometime not focused on Python. https://theconsensus.dev/p/2026/03/12/mojos-not-yet-python.html https://theconsensus.dev/p/2026/03/12/mojos-not-yet-python.h...
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- embedding-shape 2mo agoFinally, gonna be a lot of fun to finally play around with, lets see how it compares to Python for ML ultimately :) The build process is quite heavy, pinning all my cores at 100% on a Threadripper 9970X for ~15 minutes which isn't so common. Curious to know what setups they've tested Mojo on so far, as I understood it to be mainly for ML/AI stuff, so commonly pretty beefy workstation, yet I'm getting warnings that it's not recognizing my GPU (RTX Pro 6000). Seems easy enough to work around by editing the gpu_mapping in MODULE.bazel so I guess isn't a huge issue. Just strange to see a really CPU-heavy build, then not recognizing a somewhat common "prosumer" GPU (common in the ecosystem and expected user audience at least).
- spmurrayzzz 2mo agoMy expectation is always that sm120 is the forgotten orphan in the mix and that I'll have to monkey-patch my way to getting things running (and its not always due to lack of tcgen05 or other "real blackwell" features, its often just failing fallback kernel paths doing things that were clearly not tested). Mojo's design goals would in theory help this problem long term, but my sm120 PTSD still lingers.
- melodyogonna 2mo agoPR here: https://github.com/modular/modular/pull/6904 https://github.com/modular/modular/pull/6904
- samuell 2mo agoI found it a bit curious that Mojo seems more readable, while at the same time less compact, than Rust. At least according to my small experiment: https://x.com/smllmp/status/2055602226240893043 https://x.com/smllmp/status/2055602226240893043
- drannex 2mo agoInteresting, I found the Rust code _far_ more readable.
- daugasauron 2mo agoI used Mojo a while back before LLM laziness kicked in and agents started writing all the code. I didn't know anything about GPU programming and it almost felt dirty how easy it was to get some performant kernels running (5070). Even I could do it. I'm in financial engineering and I feel like mojo is definitely the language for that field in the future, especially with the relatively easy python interop for legacy stuff.
- nulltrace 2mo agoAnything in our stack is modern C++ if we can help it. If Mojo can replace those kernels without the Python runtime sitting underneath, even better.
- funnygiraffe 2mo agoI wonder how much chance of broader adoption Mojo has now when seemingly everyone has succumbed to that LLM laziness.
- bahmboo 2mo agoCan we get back the many thousands of hours wasted by humans holding their noses and pronouncing Lattner as an open source fraud?
- dekdrop 2mo agoHow is Mojo compared to Julia?
- doodlesdev 2mo agoWow. I've been waiting years for this, ever since Modular first announced Mojo. To be entirely honest, I thought they would walk back on this promise and so I never really gave the language a chance. With this and the 1.0 release, it looks like a better time than ever to start taking a look into it.
- naive_newspaper 2mo agoThis is exciting
- zapzupnz 2mo agoCue responses from all the people a week ago moaning about it not being open source on day one, despite there being a precedent from Chris Lattner that it would all go down exactly like this.