A week ago we reported on the open-source GPU drivers causing headaches for KDE users
when attempting to use the KWin compositing manager under certain conditions. Version 4.5 of the KDE Software Compilation has a few improvements to KWin and while the compositing manager does check for optional OpenGL extensions, the open-source Mesa drivers don't always do things right and it's resulted in some bugs and other issues inflicting KDE users.
Martin Gräßlin has now written a follow-up blog post to clear up some of the KWin / OpenGL problems
. In this new blog post he covers the OpenGL frame-buffer object and GLSL (GL Shading Language) changes done within KWin for KDE SC 4.5, the lack of communication between KWin and Mesa developers, Mesa shipping broken extensions, and the OpenGL 3.x compositing support in KDE 4.7
, among other related items.