X11 and XFree86 were initially developed on Unix-based systems. Usually Unix systems provide a rich number of tools and utilities to get certain things done. Under OS/2, these tools are not installed, but ports are available which are sometimes functionally equivalent to Unix utilities with the same name, but also differ sometimes in a subtle way. This guide will give you hints if you intend to rebuild the system from scratch under OS/2.
Please also read README.OS2 for end-user information, and set at least the environment variables described there.
At the current time, the most recent version available is XFree86-3.3.6. This is a full and unrestricted version which comes with complete source code. 3.3.6 is not only a bugfix release, but also supports new hardware, some of which might not even supported by OS/2 itself. See the RELEASE NOTES document for details.
If you want to join the XFree86 developer team, e.g. to add support for certain hardware, please send a request to [email protected]. Please think about such a step carefully before, though, since much work is involved. Please use the XFree86-3.3.6 source code as a test example how to compile the system. The ability to manage that is a basic requirement for becoming a developer.