RHDL - Ruby Hardware Description Language
RHDL looks similar to VHDL - there are processes which can have sensitivity 
lists, and signals.
In the examples subdirectory you'll find a couple of examples: 
counter.rb and structural.rb
(the other examples there are 'old-style' RHDL and have not been updated 
to the new style yet, so don't bother with them for now)
To run the counter example:
> ruby counter.rb
Other examples which are now up to date:
./examples/structural.rb
./examples/state_machine.rb
./examples/dff.rb (NOTE: you need to install ParseTree to run this one
                     sudo gem install ParseTree )
./examples/latch.rb
(also see: ./lib/hardware/RHDL/clkgen.rb for the clock generator example)
NOTE: docs are not currently completely up to date.  
(now moved to git 11-7-2009)
philtomson@gmail.com
Phil