OpenDX
Open source visualization software package based on IBM's Visualization Data Explorer.

Open CASCADE
A geometric modeling SDK available on Linux including geometric data structures, modeling algorithms and a shape viewer.

Chart2D
A library written in Java for adding two dimensional charts to Java programs.

RTEQ
A free (GPL) Real Time Equalizer.

Elementary Particle Project
Various open source screen savers.

4P: Pixel Pushing Paint Program
A clone of the Amiga version of the Electronic Arts' product, "Deluxe Paint". A low-resolution, low color-depth paint program.

Project IDOL
An OpenGL project done under the Linux system that tries to develop an open source CAD software.

DIB Components
Delphi drawing components. Source code, help files, demos, and templates from Droopy Eyes Software.

Coriander
Coriander is the GUI that lets you control and view the output o an IEEE1394 Digital Camera

The Gimp
The GNU Image Manipulation Program, for X Windows systems. Official site, including download area, documentation, FAQs, and a plugin registry.

Blender 3D
Ccross platform 3D software solution from modeling, animation, rendering and post-production to interactive creation and playback.

Terrain Editor
An open-source OpenGL-MFC program for the creation and texturing of landscapes.

MayaVi
Scientific data visualizer written in Python

3D Scene
Illustrates most of the modeling, illumination, and rendering 3D objects. Covers Z-buffer, Shading, Phong illumination, and Ray Tracing.

Fandango
Python scripted 3D CAD engine. Description, requirements, download, links.

JPEG Pixel Interpolator
Interpolate defects (pixels, dots, stripes) in JPEG images with minimal quality loss.

Height Map Editor
Edits, generates, and manipulates terrain height maps. These can be used in terrain renders, which are used in games, applications, and demos. Web based manual available. [Windows and Linux]

Virtainer
Open source project vizualizing container terminals (C++) [Linux, Windows]

Altaxo
Data analysis and plotting program (C#) [Windows].