[jdev] parsing xml (xmpp) with ruby

[Steven Parkes]

> IIRC the new Ruby runtime (2.0) has real threads.

Ruby 1.9 and above uses kernel threads rather than green threads, but it
still has a global interpreter lock that keeps ruby code from executing
concurrently. Sometimes things like C extensions can, and, of course, I/O
can. As someone mentioned, even Ruby 1.8 can get some amount of concurrent
I/O/computation since it implements synchronous I/O via async I/O. This
doesn't work for embedded I/O a la DNS though.