PWGL is a free visual language based on Common Lisp, CLOS and OpenGL, specialized in computer aided composition and sound synthesis. It is programmed using the Lispworks programming environment and runs under Mac OS X.

PWGL integrates several programming paradigms (functional, object-oriented, constraint-based) with high-level visual representation of data and it can be used to solve a wide range of musical problems. PWGL is based on many concepts and ideas that were originally developed for PatchWork (Laurson, Rueda, Duthen, Assayag, Agon) and thus credit should be given to numerous programmers, composers and researchers that were involved in this project. Currently, PWGL is being developed by Mika Kuuskankare. The original research team consisted of Mikael Laurson, Mika Kuuskankare, Vesa Norilo, and Kilian Sprotte.