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. There is an outdated Tk back end, and some interest in development of a Qt back end. For rendering, Chaco uses Kiva, which is a Python vector drawing API, similar to Quartz, PDF, and Cairo; like Chaco, Kiva presents a common API across different back ends.
Chaco is currently at version 3.0.