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WebAssembly is portable, stable, and well-specified. LLVM IR is not portable (it is platform-specific), not stable (it changes between LLVM versions), and not w

WebAssembly is portable, stable, and well-specified. LLVM IR is not portable (it is platform-specific), not stable (it changes between LLVM versions), and not well-specified (especially around undef). Therefore, WebAssembly is a good distribution format, LLVM IR is not.

MBCook 7y ago
We already have a portable, stable, well specified cross platform language. It’s called Java. What extra benefit does this provide, except avoiding Oracle?
- jchw 7y ago
  Oh good point, we can just embed the JVM into browsers instead. WebAssembly’s cancelled everyone! Jokes aside, why are you comparing these two very different virtual machines? WASM is a general purpose VM, JVM is not. For example, you won’t find a Rust JVM target any time soon. (Not to suggest that the JVM is strictly limited to Java, it isn’t obviously, but it is not nearly as suited to being a target for lower level languages. Also, the security model is very different.)
  - gravypod 7y ago
    I think it is experimentally possible to target Rust -> LLVM -> JVM using this project https://github.com/davidar/lljvm https://github.com/davidar/lljvm
    - jchw 7y ago
      In fact there’s almost certainly more ways, too. You could probably transpile WASM to JVM bytecode. These things are most useful when you already are in the JVM anyways, I can’t imagine most people writing software in pure Rust would jump for this, especially given that WASM has a lot to offer for this use case already and has good momentum. I see it as a better fit, with useful security guarantees and a simple design.
      - gravypod 7y ago
        The benefits of the JVM still stand out to me personally. Run anywhere, generate machine code at run time most place, world class optimizing compiler, battle tested & ready to deploy, integration with existing code base for gradual rewrites, etc. Wasm is a good idea but it's going to need to reimplement a lot of existing code (optimizing + jit). Doable and maybe it will convince people to do what has been a great idea first widely deployed by Java: compiled language in an abstract machine.
        jchw 7y ago
        The JVM had many chances to realize that goal. Java applets, J2ME, etc. I’m not sure which particular issue really kept it from keeping mindshare. I don’t think the virtual machine itself was ever really the problem. Still, since the Java platform didn’t capture this use case of a general purpose abstract machine, it makes a whole lot of sense to develop something like WASM. It’s a much more neutral platform to build on. In particular we actually don’t need to go through all of the things Java went through; we have a wealth of knowledge about what things work and what things don’t work so well. Yes, its a new JIT, but not that new: from my understanding typically the JavaScript JIT machinery is reused for the WASM JIT in browsers.
        saagarjha 7y ago
        > I’m not sure which particular issue really kept it from keeping mindshare. The fact that it was bundled as a browser plugin, mostly.
        soup10 7y ago
        java browser plugins have always been poorly designed and implemented
        snek 7y ago
        in v8 at least, we just plugged wasm into v8's existing jit. no need to make a new one from scratch.
        imtringued 7y ago
- alangpierce 7y ago
  Wasm bytecode is lower-level than JVM bytecode, so I believe it's a much easier compilation target for a variety of source code languages.
  - sanxiyn 7y ago
    Not really. NestedVM http://nestedvm.ibex.org/ http://nestedvm.ibex.org/ had no problem targeting GCC to JVM.
- snek 7y ago
  We already tried JVM in browsers, remember java applets? I sure remember the security and compatibility problems :) WASM has been designed from the ground up with portability, security, and stability in mind. It is also a lower target than JVM bytecode, which makes it more suitable to represent languages like rust and go. It has also been designed to take advantage of the sandboxed JIT engines that browsers already have for running javascript. Additionally, WASM is an open standard that anyone can contribute to, which is something that is greatly valued on the web.
  - protomyth 7y ago
    We already tried JVM in browsers, remember java applets? I sure remember the security and compatibility problems :) Actually, we didn't really try JVM in the browser. We tried it as a plug-in like Flash. The JVM didn't have access to the DOM like Javascript and WASM will have.
    - pjmlp 7y ago
      Actually it did.
      - protomyth 7y ago
        Which browser gave the JVM the same access as Javascript because it sure wasn't Netscape.
        pjmlp 7y ago
        All of them, given the right access permissions. Better read the documentation? https://docs.oracle.com/javase/tutorial/deployment/applet/manipulatingDOMFromApplet.html https://docs.oracle.com/javase/tutorial/deployment/applet/ma...
        protomyth 7y ago
        given the right access permissions. So, none of them out-of-the-box like Javascript. Given, it didn't really work as far out as 2005[1] which is 10 years after Javascript was introduced, I stand by my original statement. 1) https://www.eclipsezone.com/eclipse/forums/t16762.html https://www.eclipsezone.com/eclipse/forums/t16762.html
- Arbalest 7y ago
  Besides the point about already trying out Java Applets, Why would you dismiss the Oracle avoidance? Oracle recently moved with Java to show a strong preference to monetising it, whereas lots of people on the web cannot afford any licencing just to be able to make stuff to run on the client machine. It is actually a very strong feature of it.
  - Twirrim 7y ago
    It's a really funny monetisation move, releasing everything as open source, putting it all in openjdk (which has been the language reference spec for a while anyway) The only bit being monetised is the Oracle compiled and distributed version of the JVM. If you don't want to pay Oracle, just use OpenJDK, which has all of the same hotspot JIT stuff.
    - Arbalest 7y ago
      Oracle could have easily done as Google has done with Android, and make sure that the client end wouldn't run without some kind of proprietary extension[a]. They are the world leaders in deploying the Ask toolbar, and with that comes the end users. It is only because we aren't using Java that we don't see this happening. a] Yes you can make android apps run on AOSP, but as many comment with regards to Huawei losing their Android licence, it will remove access to a lot of API infrastructure that isn't even Google specific. edit: * caused formatting rather than being a note
      - pjmlp 7y ago
        I never had Ask Toolbar on my computer, why would you ask? 1 - I always read what I get proposed to install and disable what I don't care about. 2 - The JDK didn't had such "feature", only the consumer JRE
        Arbalest 7y ago
        Yeah I know, it was in jest, as a reminder as to the practices of Oracle. Also most consumers do use the JRE, and the size of the audience is what Oracle would make decisions on.
- johncolanduoni 7y ago
  Which Java opcode is for accessing linear memory again? I keep missing it somehow in these discussions...
  - sanxiyn 7y ago
    They are aaload and aastore.
    - legulere 7y ago
      They access arrays. CIL can access native memory, but then it's not sandboxes anymore.

MBCook 7y ago

We already have a portable, stable, well specified cross platform language. It’s called Java. What extra benefit does this provide, except avoiding Oracle?

jchw 7y ago
Oh good point, we can just embed the JVM into browsers instead. WebAssembly’s cancelled everyone! Jokes aside, why are you comparing these two very different virtual machines? WASM is a general purpose VM, JVM is not. For example, you won’t find a Rust JVM target any time soon. (Not to suggest that the JVM is strictly limited to Java, it isn’t obviously, but it is not nearly as suited to being a target for lower level languages. Also, the security model is very different.)
- gravypod 7y ago
  I think it is experimentally possible to target Rust -> LLVM -> JVM using this project https://github.com/davidar/lljvm https://github.com/davidar/lljvm
  - jchw 7y ago
    In fact there’s almost certainly more ways, too. You could probably transpile WASM to JVM bytecode. These things are most useful when you already are in the JVM anyways, I can’t imagine most people writing software in pure Rust would jump for this, especially given that WASM has a lot to offer for this use case already and has good momentum. I see it as a better fit, with useful security guarantees and a simple design.
    - gravypod 7y ago
      The benefits of the JVM still stand out to me personally. Run anywhere, generate machine code at run time most place, world class optimizing compiler, battle tested & ready to deploy, integration with existing code base for gradual rewrites, etc. Wasm is a good idea but it's going to need to reimplement a lot of existing code (optimizing + jit). Doable and maybe it will convince people to do what has been a great idea first widely deployed by Java: compiled language in an abstract machine.
      - jchw 7y ago
        The JVM had many chances to realize that goal. Java applets, J2ME, etc. I’m not sure which particular issue really kept it from keeping mindshare. I don’t think the virtual machine itself was ever really the problem. Still, since the Java platform didn’t capture this use case of a general purpose abstract machine, it makes a whole lot of sense to develop something like WASM. It’s a much more neutral platform to build on. In particular we actually don’t need to go through all of the things Java went through; we have a wealth of knowledge about what things work and what things don’t work so well. Yes, its a new JIT, but not that new: from my understanding typically the JavaScript JIT machinery is reused for the WASM JIT in browsers.
        saagarjha 7y ago
        > I’m not sure which particular issue really kept it from keeping mindshare. The fact that it was bundled as a browser plugin, mostly.
        soup10 7y ago
        java browser plugins have always been poorly designed and implemented
      - snek 7y ago
        in v8 at least, we just plugged wasm into v8's existing jit. no need to make a new one from scratch.
      - imtringued 7y ago
alangpierce 7y ago
Wasm bytecode is lower-level than JVM bytecode, so I believe it's a much easier compilation target for a variety of source code languages.
- sanxiyn 7y ago
  Not really. NestedVM http://nestedvm.ibex.org/ http://nestedvm.ibex.org/ had no problem targeting GCC to JVM.
snek 7y ago
We already tried JVM in browsers, remember java applets? I sure remember the security and compatibility problems :) WASM has been designed from the ground up with portability, security, and stability in mind. It is also a lower target than JVM bytecode, which makes it more suitable to represent languages like rust and go. It has also been designed to take advantage of the sandboxed JIT engines that browsers already have for running javascript. Additionally, WASM is an open standard that anyone can contribute to, which is something that is greatly valued on the web.
- protomyth 7y ago
  We already tried JVM in browsers, remember java applets? I sure remember the security and compatibility problems :) Actually, we didn't really try JVM in the browser. We tried it as a plug-in like Flash. The JVM didn't have access to the DOM like Javascript and WASM will have.
  - pjmlp 7y ago
    Actually it did.
    - protomyth 7y ago
      Which browser gave the JVM the same access as Javascript because it sure wasn't Netscape.
      - pjmlp 7y ago
        All of them, given the right access permissions. Better read the documentation? https://docs.oracle.com/javase/tutorial/deployment/applet/manipulatingDOMFromApplet.html https://docs.oracle.com/javase/tutorial/deployment/applet/ma...
        protomyth 7y ago
        given the right access permissions. So, none of them out-of-the-box like Javascript. Given, it didn't really work as far out as 2005[1] which is 10 years after Javascript was introduced, I stand by my original statement. 1) https://www.eclipsezone.com/eclipse/forums/t16762.html https://www.eclipsezone.com/eclipse/forums/t16762.html
Arbalest 7y ago
Besides the point about already trying out Java Applets, Why would you dismiss the Oracle avoidance? Oracle recently moved with Java to show a strong preference to monetising it, whereas lots of people on the web cannot afford any licencing just to be able to make stuff to run on the client machine. It is actually a very strong feature of it.
- Twirrim 7y ago
  It's a really funny monetisation move, releasing everything as open source, putting it all in openjdk (which has been the language reference spec for a while anyway) The only bit being monetised is the Oracle compiled and distributed version of the JVM. If you don't want to pay Oracle, just use OpenJDK, which has all of the same hotspot JIT stuff.
  - Arbalest 7y ago
    Oracle could have easily done as Google has done with Android, and make sure that the client end wouldn't run without some kind of proprietary extension[a]. They are the world leaders in deploying the Ask toolbar, and with that comes the end users. It is only because we aren't using Java that we don't see this happening. a] Yes you can make android apps run on AOSP, but as many comment with regards to Huawei losing their Android licence, it will remove access to a lot of API infrastructure that isn't even Google specific. edit: * caused formatting rather than being a note
    - pjmlp 7y ago
      I never had Ask Toolbar on my computer, why would you ask? 1 - I always read what I get proposed to install and disable what I don't care about. 2 - The JDK didn't had such "feature", only the consumer JRE
      - Arbalest 7y ago
        Yeah I know, it was in jest, as a reminder as to the practices of Oracle. Also most consumers do use the JRE, and the size of the audience is what Oracle would make decisions on.
johncolanduoni 7y ago
Which Java opcode is for accessing linear memory again? I keep missing it somehow in these discussions...
- sanxiyn 7y ago
  They are aaload and aastore.
  - legulere 7y ago
    They access arrays. CIL can access native memory, but then it's not sandboxes anymore.