"Originally, X.Org 7.4 was set to be released in March of 2008 with features that included XGE (X Generic Events), XACE (the X Access Control Extension), RandR 1.3, more PCI reworking, XKB 2, a DRI memory manager, and Glucose. However, many of these features didn't end up getting integrated into X.Org 7.4. It wasn't until February that Red Hat's Adam Jackson had stepped up to the plate with some release plans and a revised target date of May. Red Hat had hoped to ship X.Org 7.4 with Fedora 9, but as the May release wasn't met, Fedora 9 ended up shipping with a pre-release. In early March was the first X Server 1.5 pre-release (1.4.99.901) that had included more than 100 changes with memory leak fixes, EXA improvements, and plenty more.
"In June, Adam Jackson was getting ready to release X.Org 7.4 by addressing some of the last minute bugs. However, Mesa 7.1 had become a requirement for building X Server 1.5. Mesa 7.1 was still in development and the latest bits of code needed to build the X Server were only available through the git revision control system. At that point, it became a waiting game for Mesa 7.1 to be released so that X.Org 7.4 could then ship with a dependency that can be easily obtained. Just days ago we finally had the Mesa 7.1 release with a new autoconf-based configuration, DRI driver enhancements, reduced dependencies between the X Server and Mesa, GLSL support for the Intel 965 series, and ATI R500 3D support. With Mesa 7.1 out the door, it finally paved the way for the X.Org 7.4 release.
"The other important part that makes up each X.Org release, the X Server, had its major update earlier this month. This release was X Server 1.5.0 but being published on the web this morning was X Server 1.5.1. The 1.5.1 release introduces a handful of bug-fixes.
