ruby-switch 0.1.0 (amd64 binary) in ubuntu raring

 ruby-switch allows system administrators to easily switch between different
 Ruby interpreters as the system-wide default Ruby. When switching, all the
 entries in the alternatives database are changed, including but not limited to
 "ruby", "irb" and "gem".
 .
 Note that ruby-switch helps sysadmins change the system-wide default Ruby, and
 requires root privileges. For letting users choose between the different Ruby
 implementations available in Debian, use the rbenv package instead.