Ruby 1.9 was released in December 2007. Effective with Ruby 1.9.3, released October 31, 2011,[27] Ruby switched from being dual-licensed under the Ruby License and the GPL to being dual-licensed under the Ruby License and the two-clause BSD license.[28] Adoption of 1.9 was slowed by changes from 1.8 that required many popular third party gems to be rewritten.