Green threads in 1.9.*

@mononcqc I strongly suggest you opine, for the love of Erlang:

<<There are definitely many reasons to prefer native threads over green threads. This is the reason why you have seen a shift from green threads to native threads in MRI, Rubinius, and the JVM. Why do you want green threads?>> There are many situations to prefer green threads over kernel threads. It's why I'm somewhat surprised that Ruby is just ditching green threads, vs. keeping them and deploying kernel threads along side them. Perhaps it's a cultural thing. Rubyists might be more concerned with things like web servers (Rails development) and what not, and perhaps haven't found want or need for green threads so much (just a guess). One reason to prefer green threads is if your application doesn't need speed up through concurrency/parallelism, rather you want a threaded solution for algorithmic purposes, convenience purposes, or other purposes. This is a crappy example, ...

Full article: http://www.ruby-forum.com/topic/4403573#1067865