Rubynuby == so many libraries, so little time

Reading this forum while trying to study the pickaxe book and teach this
old dog some new tricks, I am at once awed and dazed by the huge number
of library’s available to the would be ruby programmer.

I was just wondering if there is a global meeting place for these
libraries, and some way (other than asking in this forum) to find a
library you’re looking for (based on what it does, rather than whatever
clever name it’s author came up with for it.)

I just experimented with google and came up with rather mixed results.
If there isn’t any well described repository somewhere, google looks
like a workable solution, but not a great one.