Version 1.9.1 of Ruby has been released. This is the first stable release of the Ruby 1.9 series. According to Yuki Sonoda, 1.9.1 "is modern, faster, with clearer syntax, multilingualized and much improved version of Ruby." Version 1.8.x is still maintained; the syntax doesn't appear completely compatible with 1.8; and many third party packages have not been upgraded yet, so unless you're maintaining one of those, you should probably hold off on upgrading for a while.