X has been multi-platform from the start. In the last 10 years, Linux has become the main, and often the only system used by X developpers. This has had consequences on the support of new features on other platforms.

In this talk we will look at the various os dependant parts of the X window system, and how they are handled on non Linux platforms. In particular, kernel support (KMS and TTM) are developed on Linux, and require large porting efforts for other platforms.

The talk will summarize the status on various platforms and the work in progress to keep up with mainstream X (and Wayland ?) development.