Kilim: Fast, lightweight, cheap message passing in Java.

Actors are decoupled from the means by which they are executed. Scala has a nice system where you can run thousands of event-based actors in a thread pool. It grows the pool as needed (as threads block). See [LINK] While it may use threads, Scala's actor system effectively allows you to create thousands of actors. Kilim is actually a pure (depending on whether you see a byte-code processing system as pure) Java system that does the same thing (as far as I can tell): [LINK] Kilim's author did a nice Google Talk: [VIDEO] EDIT: Fixed some grammar and added video link.

"Asynchronious message passing is old and great idea. Instead of synchronizing objects and dealing with deadlocks we try to isolate objects and let them exchange messages. Erlang proved it to be extremly powerful tool applicable to wide range of highly scalable mission critical applications. In JVM landscape big interest to this approach started after introducing Scala actors. " That statement is so very poorly informed! JMS ("surprise"?) has been a sign of "interest" in "Asynchronious message passing" in the "JVM landscape". I am not up on my Scala, but the author fails to convey (based on what I do know ;) the competence level that would lend weight to his attempt to address (much less support) the topic. For those interested in other JVM alternatives, Kilim seems quite promising and seems to hold its own quite well in benchmarks against Erlang. [LINK] [VIDEO] [LINK] [scroll to end to see the impressive results for Kilim.] [LINK] [edit: added pdf link]

SPEED :: In defence of Java, it is very quick when done right. See Kilim[1] for examples. SUPPORT :: On top of the speed Java has a supported hardware stack (Solaris). So if doing 100K connections is important to you, you can find engineers who can diagnose difficult problems on your whole stack. -------------- [1] [VIDEO] at 23:23 . Java is quick without Kilim too, this is just an example with stats.

Erlang is a CSP system, first and foremost, and not actors. [CSP style concurrency on JVM]: [VIDEO] (Kilim, it should be noted, was benchmarked as scaling better than Erlang/OTP.) [LINK] (paper in top comment is worth the read.) Disclaimer: I think Erlang/OTP rocks. But JVM has its moments, as well, and in fairness has earned the "most advanced VM" title.