The first alpha release of dramatis hit the streets today.
dramatis is a library available in Python and Ruby used to write concurrent
programs based on the actor model of concurrency.
The dramatis web site is http://dramatis.mischance.net
The release is available as a python distutils package at
http://pypi.python.org/pypi/dramatis. It supports both Ruby and Python, and
comes with API docs, several examples, and a tutorial.