List Recv wrote:
 > I'm looking for a fast way to "reset" Ruby.  That is, to reset the
 > interpreter back to a fresh state, or, even better, a fresh state +
 > keeping some required ruby-gems.
 >
 > My goal is to make a continuous test runner, and avoid the overhead of
 > having to restart ruby and require the gems each times.

One thing you could do would be to load up all of your libraries and 
pause on the terminal waiting for user input. As soon as the user 
unpaused the process it would load in the test cases and run them. As 
the user was looking at the output and fixing tests you could load up 
another instance and pause waiting for user input. Stir and repeat...

I've thought for a long time that something like this would be very 
useful for Rails testing where loading up the library code takes 2-3 
seconds, making unit testing tedious.

--
John Long
http://wiseheartdesign.com