The Symfony project (www.symfony-project.org) currently maintains three versions of their framework, 1.0.19, 1.1.6, and 1.2.2. 1.x versions are major releases, while 1.x.y versions are normally bug and security fixes. I would like to suggest that Symfony is slotted. Many incompatibilities exist between the 3 major versions and it is common to have existing code for the 1.0 branch that doesn't function with 1.2, yet want to use 1.2 on new projects. I've attached 3 modified ebuilds that slot each major version.
Created attachment 180491 [details] ebuild for 1.0.19
Created attachment 180492 [details] patch file for files directory for 1.0.19
Created attachment 180494 [details] ebuild for 1.1.16
Created attachment 180496 [details] patch for files directory for 1.1 series
Created attachment 180497 [details] ebuild for 1.2.2
Created attachment 180498 [details] patch for files directory for 1.2 series
These versions are no longer supported upstream.