There are as many ways of creating visual stimuli as there are vision experimenters. Here I have listed all current solutions that I know of. If you know of others, let me (astraw@users.sourceforge.net) know.

At a first instance, check out Hans Strasburger's "Software for visual psychophysics" webpage, which has much more coverage than this page. I have here mainly limited listings to projects that appear to be under active development or support.

The PsychToolbox is a great, free program that uses Matlab to display stimuli. Historically it is a Mac OS Classic application, but now a Windows port is available. A native OpenGL Mac OS X version is on its way. (Source code is available but not open source according to the Open Source Initiative.)

PsyScript is a Macintosh program for generating stimuli. Free, open source (GNU Public License). Uses AppleScript and a language based on ECL (experiment control language).

Psyscope (classic Mac OS) users will be pleased to note Psyscope X, is being ported to Mac OS X under the GNU GPL.

Presentation Free (no longer appears to be free: 12/2005) Windows based stimulus generation. Uses DirectX.

WinVis web-based and Matlab based stimulus generation programs.

VSG uses proprietary hardware and software to generate stimuli. It lacks any hardware-accelerated 3D features.

OpenRT and OpenRT-3D OpenGL stimulus generation. Free, open source. (These links do not work any more... but there is OpenRT at http://www.openrt.de/, which is an OpenGL-like project used for real-time ray tracing).

PsychoPy uses python and OpenGL together. Free, open source.

PXLab a collection of Java classes for running psychological experiments. Free.

Guimigolus is a free extension to VisionEgg, that is able to guarantee framelossless presentation of Stimuli. We were able to create stimuli that run for 13 hours at 200Hz with not one frame lost on a Win2k-System. This extension provides the programmer with a cpu-meter showing the time used for each frame, which is a great aid to time critical development. It has a very complex and great algorithm for measurement of buffer overruns. Not much documentation, and only german one, because we developed it in a course at the Carl v. Ossietzky University Oldenburg/Germany. Authors are Daniel Migowski and Guido Scherp. Download the file here: http://artis.uni-oldenburg.de/~migo/Guimigolus-0.7.win32.exe

We won't develop Guimigolus any further, so we give it away now under GPL. Maybe it helps someone.