This topic describes the X Window System application programming interface (API). Using the X Window System API, you can write applications in the MVS™ environment that can be displayed on X11 servers on a TCP/IP-based network. The X Window System API also provides the applications with graphics capabilities as defined by the X Window System protocol.

X11 and Motif libraries are based on the X Window System Version 11 Release 6.6 and Motif Version 2.1.30. Applications are supported in 31-bit and 64-bit mode. For compatibility with applications written for prior releases, X11 R6.1 and Motif 1.2 libraries and corresponding header files are also provided.