Web-based protein structure viewer and analysis tool
FlightGear Flight Simulator: free open-source multiplatform flight sim
An interactive viewer for three-dimensional chemical structures.
very good CAD software
svg editor: Easily create documents for math, physics, chemistry...
JavaScript-Based Molecular Viewer From Jmol
Fractals generator with powerful functionality.
Free OMR - OCR web sofware based on javascript and PHP
MathJax support for MathML content embedded in SVG documents
OSGeo project deegree