Lambda the Ultimate

As far as I can tell, Scala sorta grew out of funnel, though scala is focused more on web services and less on the "functional nets" notion.

Also worth mention is Inheritance in the Join Calculus (extended abstract on 13 pages).

When I heard about C# join-calculus implementation about half a year ago (Java's implementation actually pre-dates C#'s), I hoped that it would cause some interest among practitioners thanks to the implementation simplicity which does not require much knowledge of the underlying theory.

Apparently, I've been wrong. The best Java 5 can offer today is semaphores, various locks, thread-safe queues and such. These synchronization primitives are called for some unknown reason 'high-level threading mechanism' in one on-line Java publication.

Various Hoare's CSP Java libraries have suffered the same fate -- lack of interest in the development communities. I do know, however, about one successfull commercial project that used a Java CSP library quite efficiently.

VC

Unfortunately, JoCaml development stopped for a bunch of reasons. One of them was that it was a fork of Ocaml 1.07, and there would be quite some work to have a version that follows Ocaml development. Another reason is that the main developer for JoCaml was a PhD student who is now a researcher in another team.

Nevertheless, the main ideas behind JoCaml are still alive. The Join Calculus has been followed by many calculi, and some implementation ideas of JoCaml are slowly making their way into Ocaml.

If you read French, you can find a lot of information about JoCaml in Fabrice Le Fessant's PhD thesis.

There are also some summer school notes that can be of interest (Disclaimer: I'm an author of this last one).

It's perhaps worth noting that although Acute has been mentioned on LtU before, at the time there were only papers. Now there's a source release for people to play with!

I've taken a cursory look at Acute's concurrency implementation. According to the manual (paragraph 9.10), the primitives are just: 'thread', 'mutex' and 'condition variable'. For the argument sake, let's forget about the distributed concurrency tool 'thunkify' and pretend we are concerned only with local concurrency.

In my opinion, this is no different from what, say, the current Java has to offer and is a huge step backwards in comparison to JoCaml with its join calculus. Acute's mecahnism is low level and, as such, prone to the usual host of problems. Even 20-year-old Hoare's CSP would have been a better idea.

I apologize if I missed something important in Acutes's concurrency mechanism -- I did not see join calculus primitives in Acute.

This is a fair observation, because Acute isn't trying to impose a particular calculus, and so has chosen to provide a rich-but-risky set of primitives. Out of those primitives, though, one can construct a module offering the semantics of any number of calculi, and in fact one of the Acute examples is indeed the Npi module, which offers semantics inspired by the Nomadic Pict language, which in turn is based on a variant of the Pi Calculus.

I wonder if it would be possible to put together, somehow, the various dialects of OCaml that people have created? I'd be particularly interested in a MetaJoCaml. :-)

Still, the resurrection of JoCaml is indeed exciting. Concurrency and distribution are too important to leave to Erlang and Oz!