QNX 4.23A or later.

(For Gamma/Photon) Photon 1.14 or later.

Linux 2.4 or later.

(For Gamma/GTK) GTK 1.2.8.

The SRR IPC kernel module, which includes a synchronous message passing library modeled on the QNX 4 send/receive/reply message-passing API. This module installs automatically, but requires a C compiler for the installation. You can get more information and/or download this module at the Cogent Web Site.

This module may not be necessary for some Gamma applications, but it is required for any use of timers, event handling, or inter-process communication.