[mmastrac]

We have this already: <applet>. As we all know, it didn't work out so well. Having a compact format for classfiles is great. Loading java.util.* for every applet is not so great. Putting .NET into the browser would repeat this horrible experiment.

Miguel and Joe and solving the wrong problem. The problem is lack of a standard, compact bytecode format for Javascript, not lack of a complex built-in set of framework classes.

Throwing a whole runtime (Mono+CLI) with all of its legacy baggage at the problem won't solve this problem. Once you provide a bytecode format for the browser, web-native tools like GWT can generate more efficient, web-native application.

Couple the JS bytecode format with a global, cryptographically-secure long-term JS cache and you've built something just as powerful as Java or .NET but without the platform impedance mismatches.

[viraptor]

Your comment confuses me. CLI-compatible languages compile into CIL, which is a well defined language and is almost equivalent to the bytecode produced from it. So the whole idea could be implemented as a .NET bytecode runner. You could implement the Java runtime using it. The number of actual classes needed to make it usable is minimal. (you need basic types really - a new profile could be created for that and web objects mapping - .net-web)

What I actually think is that if you add a standard bytecode to JS and a global JS cache, you get the same effect as with a stripped CLI profile. Why not reuse something existing since we've got both the VMs and the standard ready?

I don't think anyone wants to throw "a whole runtime (Mono+CLI)" at the problem - the core of it is enough. I'm not sure what is the legacy baggage you're referring to either.

[mmastrac]

CLI might be well-defined, but you're going to have to implement this VM from scratch in every browser on top of the existing JS VMs. Alternatively you could ship the same VM code with every browser (unlikely - hasn't happened for JS yet) and now you've got two VMs running in every browser with twice the surface area for bugs and security exploits.

Now that you've got the CLR running in the browser, you've got to figure out a way to map it to the existing JS semantics. Microsoft's existing JScript.NET mapping isn't cleanly compatible with the prototype-based inheritance of the Javascript you're writing.

Re: legacy baggage, see:

- the parts of the basic .NET framework that shipped with 1.x and were effectively deprecated during the switch to 2.0, ie: System.Collections vs. System.Collections.Generic.

- the DLL specification, in which .NET assemblies are wrapped.

If you're not shipping a framework, what do you win by shoehorning an existing bytecode specification into the browser, except not having to write that bytecode specification again?

The web has different requirements than a desktop/server application and needs a runtime built for the web.

[viraptor]

I think that [a well designed bytecode + VM modification (current JS VMs aren't really designed to run from bytecode) + implementing global cache] is more work than [creating a mapping / compiler from JS to CIL + creating a stripped down profile]. The second option does not require big redesigns, room for incompatibilities, etc. JScript.NET might have some compatibility problems, because it started before the proper DLR - a new, clean mapping would be better. Also a new mapping independent from MS would be preferable.

I don't see the problem with legacy baggage though - you don't have to ship all classes. Stripped profiles such as Compact Framework for handhelds have been already created - there's nothing stopping people from creating a new one for the web. The DLL point is a bit moot - it's just a wrapper, it works. If it's too much overhead, you can start sharing the CIL itself instead (the content is standardised afair).

You win a common execution environment. You proposed a common bytecode, but there are only so many ways in which you can implement the runtime environment in that case - each opcode has to be precisely defined. Even if each browser implemented their own, it would most likely be a complete engine redesign with very limited current code reuse. They'd have to either create everything from scratch, or reuse (for example) the DLR and CLI and implement the JS -> DLR compiler on top of them. So that's exactly what you win - not doing everything from scratch.

[mmastrac]

Many VMs are designed to run from bytecode. This is true for Squirrelfish (Safari) and TraceMonkey (Mozilla), though V8 compiles directly to machine code. The bytecode isn't compatible, but it's not a stretch to imagine a JS bytecode language would be similar to these current IRs:

http://webkit.org/specs/squirrelfish-bytecode.html

https://developer.mozilla.org/en/spidermonkey/internals/trac...

Anyways, I still believe that shipping an existing VM, be it .NET's CLR, Java's JVM or Python's bytecode isn't the right way to go. There's a lot of innovation left on the current web platform - both in terms of the performance work that browser vendors are pushing out and the new desktop APIs that the admittedly slow web standards committees are publishing. In the case of a platform as wide as the web, it makes sense that browser vendors sit back and built something from scratch.

[mojuba]

Then LLVM is as viable an option as JVM and CLI. Even better, it's open-source and not committee or corporation-driven. And from the political point of view, once LLVM finds its way into Safari (very good chance) then Firefox and/or Chrome, consider the problem solved. I think this idea is brewing somewhere right now, it's too obvious.

[viraptor]

LLVM is not an alternative to JVM/CLI in any interesting way. It's too low-level. It doesn't provide memory management, introspection, loading, etc. It's just a compilation target really. LLVM has no dynamic features either.

[olsonjeffery]

Yeah.. no. Another commenter already pointed out the issues with llvm being too low-level.. regarding the cli and "open source"... mono is open source in every sense of the word (lib and runtime are mit.. c# compiler is lgpl).. the runtime spec is committee driven, true.. but so is the javascript language.

As for apples investment in llvm: and? Your speculation that it could be used in safari, presumably for squirrelfish, is about as unfounded as the assertion that ecma is plotting a coup by switching from is to ecma.. if you have links to the contrary, ill be happy to eat my hat, not to mention learn how llvm is useful in this space.

also, to understand just how much fun llvm can be, take a look at unladen swallow.. there are major RAM and binary size bloat issues without the corresponding speed increases, currently. Maybe it'll get better, I don't know.

Anyhow.. if the cli were a browser standard then MS could use .net in ie and everyone else could use mono .. wouldn't be perfect ill allow.. but its better than a bunch of incompatible, dialling javascript VMs. Perhaps.

Will never happen of course, but one can always dream.

[mojuba]

LLVM may be a bit immature at this stage, true. Then let's look at CLI/C#.

We don't know what patents are there kept in Microsoft's backyards. For one thing, Microsoft is not interested in supporting any technology or product other than theirs, and we know they will do everything to promote IE and kill competition at any cost. Just imagine for a moment Microsoft caring about how smoothly C# runs in Firefox on Linux. As French say, "impossible".

I don't trust them. And Mono is a Trojan Horse, thankfully not as popular and robust as it could (should?) be in principle.

Note that I don't mind the technology itself. C# is neat ("not my style" though), CLI is pretty fast, and they both play nicely with Windows. C# applications in general are smoother and faster than Java-based ones. Love the results. It's just that any port to other OSes will look worse than on Windows, with or without Microsoft's participation.

[misuba]

Only if what you want to do fits into a wee box. If you want to break out of that box and work with a web page directly, JS is still your only option. Abstractions are possible via LiveConnect (the very thing JavaScript was named for - ability to communicate with applets!), but abstractions 1) leak, and 2) suck.

So: no. What we do have, however, is a number of shots, scattered throughout Mozilla's history, at getting other languages into the browser that crashed and burned. Maybe Miguel has the pull to get uptake for something like this, but I'm skeptical.

[cturner]

    JS is still your only option

There did used to be a way of bridging from applet into javascript. It was introduced in netscape, and IE added support. It allowed you to have business logic in java (including custom jars, such as for middleware) sending instruction to the DOM layer. But firefox didn't reimplement it, and it was dropped from IE too. I worked on a business system that worked like this for a while. I think they rewrote it later to use webstart and swing.

[Chris_Newton]

It is certainly possible to communicate between Java applets and JavaScript, and in a widely portable way. One of my current projects does it all the time, for much the reason you suggest: it means I can have the model in a well-structured Java system, but branch out to JavaScript for the parts of the UI where it is helpful.

To call from JavaScript to Java, you can just use the public members of the applet object.

To call from Java to JavaScript, you can use JSObject.

Aside from working around a few minor gremlins in particular browsers, most of the basic things you'd want in this context "just work". In practice, when I'm transferring big chunks of highly structured data from the Java model to views using JavaScript, I use an intermediate layer in the applet that looks up all the relevant data Java-side and builds a JSON representation that is trivial to work with in JS, which avoids any trickiness with things like marshalling arrays and means rendering specialist types in Java world into suitable strings or objects in JS is all done in one place according to consistent rules. This all runs fine on IE, Firefox, Chrome, etc.

The biggest practical problem I've found is that because relatively few people are doing this for major projects, there is also relatively little documentation around on the web (including the official Java pages and the developer pages for the various browsers). That means if you do run into one of the awkward cases, it's not always a five-second search to find the answer. Still, so far I've been doing this for over a year, using the same techniques in a couple of different contexts, and most of the problems with "incompatibility" have quickly been resolved by updating to the latest versions of things.

[bruceboughton]

Does anyone have links for this?

[cturner]

I think it was 'JSObject'.

http://www.rgagnon.com/javadetails/java-0172.html

http://java.sun.com/products/plugin/1.3/docs/jsobject.html

[10ren]

I like the JS bytecode idea, but it won't be as powerful as Java or .NET in terms of performance.

Pertinent example: Flash improved its performance enormously from AS2 (ActionScript) to AS3, and one thing they did was add type info. Pertinent because AS is JS.

[mmastrac]

ECMAscript 4 was supposed to bring these features to Javascript, but it ended up dead due to standards-committee politics:

http://ajaxian.com/archives/ecmascript-edition-4-brendan-spe...

http://weblogs.mozillazine.org/roadmap/archives/2007/10/open...

http://ajaxian.com/archives/the-future-of-ecmascript-3-is-4

[fauigerzigerk]

No, not just due to standards-committee politics. Many people didn't like ECMAScript 4 for good reason. I read the spec. It's monstrous. I have hardly ever seen a language with so many overlapping, redundant, completely pointless language features. I'm glad it's dead and I hope it doesn't become undead one day.

[jules]

A bytecode specifically for Javascript would probably be sub optimal for performance of non-javascript languages. I'd rather have something lower level like .NET/Java bytecode or perhaps even LLVM.

[blasdel]

A bytecode for JS would be more optimal for other languages than the status quo: compiling to lexical javascript.

I they added a few extra bytecodes for stuff like TCO or goto or integers, it'd be pretty fantastic.

[Silhouette]

> We have this already: <applet>. As we all know, it didn't work out so well.

I hear that a lot, but I think Java applets didn't gain widespread traction more because of the arrival of Flash as an easier format for simple animations and interactions than anything else.

Java applets remain a useful tool for browser-based UIs today; one of my current projects involves writing one. The biggest technical hurdle is that not everyone installs a modern JRE with their browser any more, which is a downer for casual use because it means there's stuff to install locally. For tools you're going to use every day it's no big hurdle, though.

The primary alternatives are Flash (which is well-established but looking more awkward and proprietary with all the current politics, and somewhat limited in its applicability) and JavaScript (which has potential, but isn't even close to being a good language for developing serious UIs of moderate or large size today, and no amount of HTML5 canvas/multimedia hype is going to change that).

[est]

> The problem is lack of a standard, compact bytecode format for Javascript,

IE can embed javascript bytecode

    <script language = JScript.Encode>#@~^EQAAAA==C^+.D`Et+^VK~CgBbgQUAAA==^#~@</script>

save the above line to 1.html and open it in IE (version<9)

it's not standard, though.

[mmastrac]

<script language="JScript.encode"> is an obfuscation mode for raw JS source, not a bytecode format:

http://www.virtualconspiracy.com/content/articles/breaking-s...