I was just talking with a coworker about this. We agreed that much of our existing C++ code could have been written in Java without harm (we're doing compute-heavy finance, but not fluid simulation), and that would let us skip a whole lot of infrastructure pain. The only uncertainty was how easy it would be to make a Java-based Excel plug-in, but Java on Windows seemed a smaller evil than C# on Linux.

F# is interesting, Scala is interesting, and we both wondered what it would be like to really try ocaml for real. But Java's just pretty solid. It's not exciting, but it's quality engineering. It makes some questionable trade-offs, but it seems to provoke more hate than it deserves.

Of course, we then rolled our eyes about all the crazy Java stuff we've seen, with XML-everywhere, FactoryFactories, and gratuitous IoC.

That started me wondering: what is it about Java that encourages the craziness? My theory is that it's a combination of garbage collection and lack of easy blocks/anonymous functions. Garbage collection lets you get away with things that you'd never try in C++, and lack of blocks means you're stuck with a pretty limited API, so you end up inventing extra-language channels for information.

Note: I intentionally didn't demand closures. I think the original blocks in Smalltalk weren't closures, but they were still useful for things like "monkeys select: [:m | m throwsPoop]". I'm not sure if this is really enough; closures make some things a lot easier.