JActor is a Java partial reimplementation of the scala project, AsyncFP, a high-performance actor implementation. (See https://github.com/laforge49/Asynchronous-Functional-Programming/wiki for more information on AsyncFP.) Message passing is mostly synchronous, at a rate of up to .8 billion messages per second. (Tests were done on an Intel Core i5 CPU M 540 @ 2.53GHz, which has 4 hardware threads. The times reported were best run in 5. Only standard switch settings were used--there was NO compiler optimization.)