Chaco is a platform-independent plotting library for Python, which is licensed under a BSD style open source license. It was originally developed developed by Enthought, Inc. for the Space Telescope Science Institute (STScI), and it has been used in a wide variety of scientific applications. Chaco's goal is to produce presentation quality scientific 2-D graphics on a variety of output devices. Chaco currently works with wxPython, Qt, OpenGL, SVG, and Cocoa (OS X) back ends.
Chaco is currently at version 3.0.