Last night I gave my 2+ hour talk on Ruby, JRuby, and JRuby on Rails to the Gateway JUG in St Louis, and it seems to have been a resounding success. We had extremely good attendance, pushing 50 folks from what I could tell, and everyone seemed to be very excited for the possibilities of Ruby on the Java platform. Many folks told me they were going to be looking into Ruby and Rails for future development, and others promised to contribute to the project however possible.
It was a great experiment for me to do this presentation, primarily because it was one long demo. There were a few slides to bridge things together, but ultimately I spent two hours typing into IRB, vi, and bash to demonstrate Ruby, JRuby, and building and running a simple JRuby on Rails app. There were a few glitches (I forgot a few metaprogramming methods, and my new migration initially failed because I ran it on an already-migrated database) but I managed to recover from everything and get all my demos across. I think the live walkthroughs coupled with a very enthusiastic and interactive crowd made a fun presentation for folks in attendance.
Afterwards I had a few beers with the locals and we shared our war stories about Java application development and excitement for a Ruby-filled future. Judging by their reactions to the talk and the stories they related, I think this JRuby thing is poised to really take off.
I've uploaded my Gateway JUG JRuby slides so you can see and share them, and Alex Miller from BEA took a transcript of the JRuby live walkthroughs.
Gateway JUG JRuby Presentation (Opendoc)
Gateway JUG JRuby Presentation (PDF)