the change in number is indicative of the significance of a release i.e. if it moves up an incremental point such as 4.8.2 to 4.8.3 then it's a small release targetting a limited set of errors/enhancements, if it moves up a minor point such as 4.8.4 to 4.9, it indicates a larger release , typically one that add's more significant features & enhancements. If it moves up a major point such as 4.9 to 5.0 then it's a major release with a large amount of change. This is fairly standard practice in opensource projects and gives users an idea of the content of a release and how much testing they should do locally before upgrading production releases. In this case the version number went from 4.8.4 to 4.9 as there were a large number of changes - approx 40 bug fixes and many enhancements.

We of course use source control to control all the dotnetnuke projects, though we do not use TFS, and we frequently work on multiple versions i.e. the 5.0 release has existed since 4.8, with the 5 releases since then being merged (when approriate) into 5.0.

Cathal