While the Catalyst driver for Windows was released a number of days ago, the Catalyst Linux driver was missing. It has, however, been released today. AMD's Linux engineers ended up delaying the Catalyst 9.3 release so they could spend additional time tuning this driver, since it will be the last release that supports the R300 through R500 series as the support is being dropped. The significant feature that was pushed back into the Catalyst 9.3 Linux driver is improved Composite support.
Catalyst 9.3 for Linux has improved support for Composite via supporting redirected OpenGL rendering under Compiz. Yes, that means for all of the Linux desktops out there running Compiz or KWin4 or other compositing window managers, the rendering is now a lot better. With the open-source drivers, redirected direct rendering is possible when using DRI2 and the related work such as kernel memory management, but the Catalyst driver does not use the Direct Rendering Infrastructure 2. The proprietary NVIDIA driver also uses its own infrastructure for dealing with redirected OpenGL rendering. With OpenGL composite support, windows and their contents should be displayed properly even when dragging around a wobbly window on a multi-sided desktop. Hurrah! As a very easy way to understand why redirected OpenGL rendering is important, first let's watch a video we recorded on Catalyst 9.2 when the advanced Compiz desktop effects were enabled from Ubuntu.
The OpenGL demo does not keep up with the moving window and it is horribly rendered. Now this is what it looks like on the same exact system immediately after installing Catalyst 9.3.
It's now a beautiful desktop! While this is great, look for the Composite support to continue to improve in the Catalyst Linux driver.