Threads in Ruby
The current (as of Ruby version >= 1.9) situation concerning threads, concurrency and parallelism in Ruby is nicely explained in this article.
The GIL (Global Interpreter Lock) in the MRI Ruby interpreter gets mentioned and its purpose of data protection is exemplified here. The same author previously published a piece that described threading in Ruby in a more general way, including the topic of fibers.
Finally, I found an interesting discussion addressing this subject in the Ruby forum.
