Automata editor is a vector editor for drawing finite automata according to VauCanSon-G format with tools for working with finite automata such as basic algorithms, exporting transition table to LaTeX format and automata work simulation.
AudioCarver is a music composition application featuring a user interface based on 3d modeling.
Open Source CAD
QCAD is an application for computer aided drafting (CAD) in two dimensions (2D). With QCAD you can create technical drawings such as plans for buildings, interiors, mechanical parts or schematics and diagrams. QCAD works on Windows, Mac OS X and many Linux and Unix Systems.