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Ask HN: Why hasn't JVM become the defacto implementation for dynamic languages?

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Ask HN: Why hasn't JVM become the defacto implementation for dynamic languages?

#1

Post by bryanalves »

The JVM has been around for a while now. It's stable, mature, and fast. Lots of languages have started to get ported over to the JVM, and things like Scala exist to make the JVM a great computing platform.

With recent dynamic language implementations on the JVM meeting or surpassing performance of the "native" VMs, why hasn't there been a move to have the JVM become the default implementation?

Jython is a great example. It's fast -- faster than CPython in a lot of cases, and it doesn't have the GIL. And it gets access to the full Java environment if it wants it, presumably including things like Clojure, JRuby, Scala, etc. where appropriate.

This seems like a win/win to me, yet there is almost no traction in this direction. I can think of a couple of reasons why this might be:

1. I'm wrong and Jython isn't actually any faster.

Even if it isn't faster, the better environment should make up for this.

2. Integration with Java land isn't that much of a benefit.

Having access to all of this stuff -- but not being forced to use it -- seems great to me. There's no real downside and lots of potential upside, including increased market penetration in enterprise environments.

3. The JVM won't benefit from dozens to hundreds of programmers from python/ruby/etc applying what they've learned in their respective languages to it.

Maybe this is a case of too many cooks in the kitchen. Linux seems to do well with the "shittons of developers working simultaneously" method of doing things, why can't the JVM?

Even if the language developers don't work on the JVM at all, so what? See points 1 and 2.

4. Lagging behind by a few versions (Jython is at what, 2.5.x?) is a bigger deal than I'm imagining.

This could be made up for within a year or 2 if languages committed to the JVM as their default implementation.

5. Non-perfect compatibility breaking lots of stuff

This is a major concern, right? It's not like Python3 isn't doing the same thing right now, or seemingly every version of Ruby doing the same thing. Oh wait, they do.

Maybe the JVM isn't the right vm to standardize on; maybe LLVM would be more appropriate. I don't know. What I do know is that it seems silly for a bunch of language designers to all be having a big case of NIH and writing their own vms and bytecode interpreters.

Thoughts?

Re: Ask HN: Why hasn't JVM become the defacto implementation for dynamic languages?

#2

Post by icebraining »

There's a recent blog post[1] by one of the CPython core devs. He talks about Pypy, not Jython, but I think it applies too:

Personally, I think the status quo in this space is in a pretty good place, with python-dev and CPython handling the evolution of the language specification itself, as well as providing an implementation that will work reasonably well on almost any platform with a C compiler (and preferably some level of POSIX compliance), while the PyPy crew focus on providing a fast, customisable implementation for the major platforms without getting distracted by arguments about possible new language features.

[1]: http://www.boredomandlaziness.org/2011/08/of-python-and-road...

Re: Ask HN: Why hasn't JVM become the defacto implementation for dynamic languages?

#5

Post by mtogo »

The JVM is mostly nonfree, controlled by Oracle, and isn't easily or readily available on systems other than Windows. I cringe whenever i see an application of some sort that relies on the JVM, as i know there's a rather small chance of that application working properly.

In theory it's great, but in practice it sucks.

Re: Ask HN: Why hasn't JVM become the defacto implementation for dynamic languages?

#6

Post by amorphid »

mtogo wrote: post #5

The JVM is mostly nonfree, controlled by Oracle, and isn't easily or readily available on systems other than Windows. I cringe whenever i see an application of some sort that relies on the JVM, as i know there's a rather small chance of that application working properly. In theory it's great, but in practice it sucks.

The JVM is available on Linux and Mac OS X, too.

Re: Ask HN: Why hasn't JVM become the defacto implementation for dynamic languages?

#7

Post by mtogo »

amorphid wrote: post #6
mtogo wrote: post #5

The JVM is mostly nonfree, controlled by Oracle, and isn't easily or readily available on systems other than Windows. I cringe whenever i see an application of some sort that relies on the JVM, as i know there's a rather small chance of that application working properly. In theory it's great, but in practice it sucks.

The JVM is available on Linux and Mac OS X, too.

Sure it's available, but it's error-prone to install, often an old version, and generally breaks all over the place.

Re: Ask HN: Why hasn't JVM become the defacto implementation for dynamic languages?

#8

Post by jp »

Sun was a supercomputer company. Java is the alternative to IBM operating system VM's running on mainframes. Nobody has that kind of hardware just lying around. Java was designed to run on $1000 SCSI hard-drives and 32Gb of RAM. The focus is on standardization, scalability, portability, buzzwords and expensive catering.

The guy that made the Chrome Javascript VM sat with a laptop in a small house in the Danish countryside. Because the focus was on normal everyday hardware. And guess who that was ? A former Sun Java VM programmer. So the "just use Chrome" developer demographic is sort of unintentionally ironic when they, well, open their mouths. Why do they think Chrome is so memory hungry anyway :P Well, the problem is actually the same problem that you have in other UI frameworks where event listeners and DOM references never gets released from the UI side. And there are some strange issues with anonymous functions and closures, but I do not know enough about that to comment.

Java is fine, but Javascript does not need to be Java. Apple just screwed up the LiveConnect bridge in Safari just to piss us off.. transition us all to a better state of mind. Or maybe that was Oracle, I have no clue anymore. The guy that worked on Jython probably felt very alone doing all the work and JRuby is only here because of desperation from Sun. And Scala is the solution for people who never finish anything. So maybe I should.. oh shiny..

http://www.businessweek.com/globalbiz/content/nov2008/gb2008... http://labs.teppefall.com/2011/08/why_not_use_java_and_invok...

Re: Ask HN: Why hasn't JVM become the defacto implementation for dynamic languages?

#9

Post by Aloha »

mtogo wrote: post #7
amorphid wrote: post #6

Earlier quoted context omitted.

The JVM is available on Linux and Mac OS X, too.

Sure it's available, but it's error-prone to install, often an old version, and generally breaks all over the place.

There are other implementations too, like IBM J9 and GNU Kaffe. I remember using J9 in place of Sun Java when I was a desktop Linux user.

Re: Ask HN: Why hasn't JVM become the defacto implementation for dynamic languages?

#10

Post by vorg »

When Oracle bought Sun, Java lost its mojo. Sure, Java still has many more installs, but who would trust Oracle with it medium- to long-term. Microsoft was clearly evil when Java was born, and in the late 1990's. But Microsoft turned, created C#, and has slowly nurtured it so it's now better than Java in many ways, e.g without Java's rotten type erasure, snappier in Visual Studio than JVM-anything in Eclipse, with the dynamic keyword, ... Now everyone knows Oracle is more evil than Microsoft, and the JVM is just one of many platforms, alongside .NET, javascript ..., we can develop to.
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