[hshiffman]

As at least some of you have figured out, the title is incorrect. Azul did not make Zing open source; we are just making free licenses available to developers working on open source projects.

Regarding performance, you can find some useful information on Azul's website. In a nutshell, Zing's strengths are its ability to GC while the application continues to run; and its ability to support very large memory heaps without a performance penalty. The two combine to permit a single JVM to do a lot more work and to avoid long application stalls when GC is triggered.