PsychoPy is an open-source application to allow the presentation of stimuli and collection of data for a wide range of neuroscience, psychology and psychophysics experiments. It’s a free, powerful alternative to Presentation™ or e-Prime™, written in Python (a free alternative to Matlab™ ).
Updated prac class materials: The PsychoPy practical class materials have been updated. The first half of the 10-class course have now been run twice and are getting more polished. Some of the second half (in which less actual PsychoPy teaching is done) are not so battle-tested but should still provide a good starting point for your own pracs. See Lecture materials (Builder)
Latest version: 1.71.01 was released Oct 2011. See complete Changelog