What were they using before? Imake?Mesa 7.1, which was the first release of this open-source OpenGL library with an autoconf-based configuration system
Phoronix: Mesa 7.2 Release Candidate 1
Released in late August was Mesa 7.1, which was the first release of this open-source OpenGL library with an autoconf-based configuration system, various DRI driver enhancements, GL_EXT_texture_from_pixmap extension for the Xlib driver, GLSL for Intel's 965 Chipset, and ATI R500 series support. This release was also important since it was a prerequisite for the X.Org 7.4 / X Server 1.5.0 release...
http://www.phoronix.com/vr.php?view=NjcyMQ
What were they using before? Imake?Mesa 7.1, which was the first release of this open-source OpenGL library with an autoconf-based configuration system
Wouldn't that usually be a 7.1.1?Mesa 7.2 is intended to be the stabilized version of Mesa 7.1, which means it incorporates additional testing and bug-fixes.
No, 7.1.1 would be a bugfix release for 7.1. That is in open source software development many projects tend to use SOMETHING.even for stable series and SOMETHING.odd for development releases. That is for example just the way we do it at Wesnoth. There version 1.4.6 is the 7th (we start counting with 0) release of the stable series which is compatible with all other versions of the stable series and basically just includes slight changes like bugfixes, updated graphics and updated translations. On the other hand there is the development series with more intrusive changes.