The following Ruby Gems are available:

actionmailer
actionpack
activemerchant
activerecord
activeresource
activesupport
ajax_scaffold_generator
archive-tar-minitar
aws-s3
Bloglines4R
BlueCloth
builder
cmdparse
color
color-tools
diff-lcs
fastthread
feedtools
ferret
flickraw
gd2
gnuplot
gruff
hoe
hpricot
htmltools
icalendar
json
login_generator
madeleine
maruku
mechanize
mime-types
mysql
PageTemplate
ParseTree
payment
pdf-writer
podcast
rack
rails
rake
RedCloth
rflickr
rmagick
rspec
rspec-rails
ruby-openid
rubyforge
RubyInline
rubyslippers
rubyzip
ruwiki
shipping
shorturl
sqlite3-ruby
syntax
Technorati-Ruby
tidy
transaction-simple
tzinfo
uuidtools
wee
will_paginate           
xml-simple