known

# MRI Rubies
[ruby-]1.8.6[-p399]
[ruby-]1.8.6-head
[ruby-]1.8.7[-p330]
[ruby-]1.8.7-head
[ruby-]1.9.1-p243
[ruby-]1.9.1[-p378]
[ruby-]1.9.1-p429
[ruby-]1.9.1-head
[ruby-]1.9.2-preview1
[ruby-]1.9.2-preview3
[ruby-]1.9.2-rc1
[ruby-]1.9.2-rc2
[ruby-]1.9.2[-p136]
[ruby-]1.9.2-head
ruby-head

# GoRuby
goruby

# JRuby
jruby-1.2.0
jruby-1.3.1
jruby-1.4.0
jruby[-1.5.6]
jruby-head

# Rubinius
rbx-1.0.1
rbx-1.1.0
rbx-1.1.1
rbx-1.2.0
rbx[-head]

# Ruby Enterprise Edition
ree-1.8.6
ree[-1.8.7]
ree-1.8.6-head
ree-1.8.7-head

# MagLev
maglev[-24924]
maglev-head

# Mac OS X Snow Leopard Only
macruby[-0.8] # the default macruby
macruby-nightly
macruby-head      # Build from the macruby git repository

# IronRuby -- Not implemented yet.
ironruby-0.9.3
ironruby-1.0-rc2
ironruby-head