PsychoPy is an open-source package for creating psychology stimuli in
Python (A real and free alternative to Matlab). PsychoPy combines the
graphical strengths of OpenGL with the easy Python syntax to give
psychophysics a free and simple stimulus presentation and control
package.

The goal is to provide, for the busy scientist, tools to control timing
and windowing and a simple set of pre-packaged stimuli and methods. The
code is platform independent, using Python and C libraries that are
widely available.

WWW: http://www.psychopy.org/