The official release of X.Org Server 1.15.0 is expected to be released by the end of December after it was delayed from its original September release target over the lack of exciting features at the time. Keith Packard of Intel has been putting out the 1.15 test releases and today he's released X.Org Server 1.15 RC4, which he's codenamed Chai after 1.15 RC3 was under the "Apple Pie" codename.
X.Org Server 1.15 RC4 "Chai" has just shy of 50 commits since the 1.15 RC3 release near the end of November. Landing for 1.15 RC4 were configure.ac updates, DRI3 Present extension changes, GLX tweaks, and tightening of the default scheduler intervals. This X.Org Server release is also trying to fallback to loading xf86-video-fbdev now prior to xf86-video-vesa, due to KMS and UEFI systems where using the frame-buffer device driver is the better choice than VESA.
Keith Packard has yet to issue an official release announcement for X.Org Server 1.15 RC4, but the code can be fetched from Git.
X.Org Server 1.15 will premiere in the weeks ahead with Direct Rendering Infrastructure 3, the GLX rewrite, and numerous other enhancements along with its share of bug-fixes and other tweaks.