Syzygy is a programming toolkit for writing virtual reality or other graphical applications using OpenGL. It's been used by ISL and other institutions for about 15 years.
Without even recompiling, a Syzygy application can run either standalone on a laptop or on a cluster of computers, just by modifying some configuration files.
Syzygy runs on Windows, Linux, MacOS X, and Irix. A cluster can mix these operating systems.
The Syzygy libraries themselves are written in C++. Syzygy applications can be written in either C++ or Python.
(As the world prepares for Git 2.0, ISL has adopted the new push.default behavior: "git config --global push.default simple".)
For more information, see the ISL software page.