Topic:Engineering/Free or open source design tools

Tools which may be useful to participants in engineering studies, research and development. Please add tools and concise evaluations as they become available.

Looks extensive, useful and increasingly so. Not terribly easy to install and maintain for a computer neophyte.
Finite element analysis package. Freeware with C source code downloadable. Program documentation available in English, German and Greek.
List of links to open source or free engineering assets.
List of Free Math tools maintained by the Wikiversity School of Mathematics
GUI based geometry editor. Includes some analytical functions, geometric shapes, conic sections and exports to several formats including SVG. Good for sketching and diagrams.
Math analysis and plotting tool for Linux/KDE desktop environment. Superimposes functions on precise plots and allows export to bmp, png, and svg.
3D CAD tool
Computer-aided engineering platform (CAD, kinematics, analysis)
Latest version at .
Screencasts created by faculty at the University of Colorado to help students study engineering topics. Also includes resources for instructors.