Java at 30: Interview with James Gosling

Java performance isn't the fastest, that's ok, a close 3rd place behind C/CPP ain't bad. And you're still ahead of Go, and 10x or more ahead of Python and Ruby.

Java syntax isn't perfect, but it is consistent, and predictable. And hey, if you're using an Idea or Eclipse (and not notepad, atom, etc), it's just pressing control-space all day and you're fine.

Java memory management seems weird from a Unix Philosophy POV, till you understand whats happening. Again, not perfect, but a good tradeoff.

What do you get for all of these tradeoffs? Speed, memory safety. But with that you still still have dynamic invocation capabilities (making things like interception possible) and hotswap/live redefinition (things that C/CPP cannot do).

Perfect? No, but very practical for the real world use case.

When I got out of college and was still firmly in the "Java is the solution to everything" mentality I didn't realize that my admiration was really for the JVM and the Java App Server tooling that was so much more advanced than anything else at the time. It was basically Docker + K8s for anything running on the JVM more than 2 decades earlier.

Java the language eventually drove me away because the productivity was so poor until it started improving around 2006-2007.

Now I keep an eye on it for other languages that run on the JVM: JRuby, Clojure, Scala, Groovy, Kotlin, etc.

IMO JRuby is the most interesting since you gain access to 2 very mature ecosystems by using it. When Java introduced Project Loom and made it possible to use Ruby's Fibers on the JVM via Virtual Threads it was a win for both.

Charles Nutter really doesn't get anywhere close to enough credit for his work there.

Let me extol the virtues of Java the language.

You can take pretty much any code written for Java 1.0 and you can still build and run it on Java 24. There are exceptions (sun.misc.Unsafe usage, for example) but they are few and far between. Moreso than nearly any other language backwards compatibility has been key to java. Heck, there's a pretty good chance you can take a jar compiled for 1.0 and still use it to this day without recompiling it.

Both Ruby and Python, with pedigrees nearly as old as Java's, have made changes to their languages which make things look better, but ultimately break things. Heck, C++ tends to have so many undefined quirks and common compiler extensions that it's not uncommon to see code that only compiles with specific C++ compilers.

Yeah, that and the portability are really incredible and underrated. It is funny, because I constantly hear things like "write once, debug everywhere", but I have yet to see an alternative that has a higher probability of working everywhere.

Although Python is pretty close, if you exclude Windows (and don't we all want to do that?).

I can run basically any Perl code back to Perl 4 (March 1991) on Perl 5.40.2 which is current. I can run the same code on DOS, BeOS, Amiga, Atari ST, any of the BSDs, Linux distros, macOS, OS X, Windows, HP/UX, SunOS, Solaris, IRIX, OSF/1, Tru64, z/OS, Android, classic Mac, and more.

This takes nothing away from Java and the Java ecosystem though. The JVM allows around the same number of target systems to run not one language but dozens. There’s JRuby, Jython, Clojure, Scala, Kotlin, jgo, multiple COBOL compilers that target JVM, Armed Bear Common Lisp, Eta, Sulong, Oxygene (Object Pascal IIRC), Rakudo (the main compiler for Perl’s sister language Raku) can target JVM, JPHP, Renjin (R), multiple implementations of Scheme, Yeti, Open Source Simula, Redline (Smalltalk), Ballerina, Fantom, Haxe (which targets multiple VM backends), Ceylon, and more.

Perl has a way to inline other languages, but is only really targeted by Perl and by a really ancient version of PHP. The JVM is a bona fide target for so many. Even LLVM intermediate code has a tool to target the JVM, so basically any language with an LLVM frontend. I wouldn’t be surprised if there’s a PCode to JVM tool somewhere.

JavaScript has a few languages targeting it. WebAssembly has a bunch and growing, including C, Rust, and Go. That’s probably the closest thing to the JVM.

Interesting about that long list of languages.

There's also Groovy.

I wonder what other languages run on the JVM. What about Perl, Icon, SNOBOL, Prolog, Forth, Rexx, Nim, MUMPS, Haskell, OCaml, Ada, Rust, BASIC, Rebol, Haxe, Red, etc.?

Partly facetious question, because I think there are some limitations in some cases that prevent it (not sure, but a language being too closely tied to Unix or hardware could be why), but also serious. Since the JVM platform has all that power and performance, some of these languages could benefit from that, I'm guessing.

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