Answer by zw963 for Does ruby have real multithreading?

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Update(2017-05-08)

This article is very old, and information is not follow current(2017) tread, Following is some supplement:

12. Opal is a Ruby to JavaScript source-to-source compiler. It also has an implementation of the Ruby corelib, It current very active develompent, and exist a great deal of (frontend) framework worked on it.and production ready. Because base on javascript, it not support parallel threads.

13. truffleruby is a high performance implementation of the Ruby programming language. Built on the GraalVM by Oracle Labs,TruffleRuby is a fork of JRuby, combining it with code from the Rubinius project, and also containing code from the standard implementation of Ruby, MRI, still live development, not production ready.This version ruby seem like born for performance, I don't know if support parallel threads, but I think it should.