Regarding the ractors, I'm a big fan - I believe true multithreading in a language with a GIL is a revolutionary change. On the other hand, I also believe that Ruby has always had a culture of single threading, so for the ecosystem to adjust (in practice, for having threadsafe libraries), it will take a very long time (if ever; I'm pessimitic and personally believe the ecosystem will never catch up, but of course, I wish all the best :)).