X Generic Event (XGE) Protocol Specification

As part of his work on Multi-Pointer X, Peter Hutterer had developed the Generic Event Extension for X.Org, or commonly referred to as XGE. The X Generic Event Extension makes it possible for clients to reuse a single event opcode, which is needed with MPX since the X Server is currently limited to supporting only 64 opcodes between all X extensions.

While MPX went mainline earlier this year, it's being disabled in X Server 1.6 since X Input 2 isn't ready. As a result, there won't actually be anything using the X Generic Event Extension in X Server 1.6. The XGE protocol specification though will ship with the server 1.6 documentation.

If you're interested in learning more about XGE, the XGE protocol specification (which is quite brief) can be read on the X.Org mailing list and there is more information about XGE on the X.Org Wiki.