JRuby threads are fully parallel and in production use today. CRuby's GIL is an implementation choice rather a property of dynamic/interpreted languages.
Is it really a "choice" if the alternative is really hard to achieve in practice? It's like calling python's GIL a choice... with numerous projects trying to get rid of it in various ways and never really succeeding to do it while keeping the single threaded performance and the extensions API.
> It is a choice to keep backwards compatibility with the C extensions API.
IIUC for CRuby it's mostly about how to keep the VM simple. Koichi Sasada is working on an ownership based model like Erlang has, which sidesteps a bunch of theses issues.
