Pentaho Branches - explanation

On git-hub currently (03-26-2014) pentaho-platform project have 11 branches:

• 5.0
• 5.0.5
• 5.0-CE
• 5.0-CE-Dev
• 5.0-OLD
• 5.1
• ...
• ...
• master

01. Can anybody explain this counted versions? Which version is best


When I fork my version (12-20-2013) pentaho-platform have 8 branches:
$ git branch -a
* 5.0
remotes/origin/5.0
remotes/origin/5.0-CE
remotes/origin/5.0-CE-Dev
remotes/origin/5.0-OLD
remotes/origin/acl-voter-story
remotes/origin/dev-local
remotes/origin/feature1
remotes/origin/master

02. Is it possible to merge my version with new versions?