Prefacing a one-liner like this with "I don't know Rails..." is just begging to be downmodded, but damn... -3? This is a rough crowd.
I only have cursory experience with Rails and Catalyst, but the first thing I noticed is that Rails is much friendlier to Ruby novices than Catalyst is to Perl novices. Still, Catalyst is pretty nice if you're a Perl developer looking for a Rails-like framework.
