I recently made the new icalendar library for Ruby which I've been working on for the past six months available on github
I plan to also put this on rubyforge (the project has been created already), but I want it to get a little more grilling from users before really pushing it out into the world, and I figure that github users might be a little more willing and understanding to work with slightly less mature code.
This is a completely new library, it's based on neither the icalendar nor vpim gems, which both do a very good job of parsing icalendar data, but don't try to do things like understanding icalendar time zones and recurring events. In ri_cal, I took those tasks as the main goals.
I've made some low-key announcements about ri_cal on my blog:
http://talklikeaduck.denhaven2.com/tag/rical
It's gotten some interest, there are currently 79 folks watching it on github. But I'd like some more bug reports!
There is a google group for discussion at http://groups.google.com/group/rical_gem anyone is welcome to join. I've set it up so that initial postings are moderated to avoid it becoming a spam trap.
There is also a lighthouse project for bug tickets: http://rick_denatale.lighthouseapp.com/projects/30941-ri_cal/overview