Lightweight threads in Java?

There is a proposal for lightweight threads ("fibers") on the JVM called Project Loom: http://cr.openjdk.java.net/~rpressler/loom/Loom-Proposal.html

It's in its early stages, nothing released yet, but still something to keep an eye on.

I am not aware of any "lightweight" solutions that would be on their way into the Java community process. See the jep entries ... no word about anything like that there. There was a request for coroutines years back; but that thing looks pretty much "dead".

I think the closest that you can get today would be more something like what the akka framework provides to you; as those Akka actors all run with a ""lightweight thread" of activity so to speak.