A simple software to read source file of (.src,.svg)Ovation/WDPF's(Emerson Process Management) Graphics Builder/Control Builder. There are also including some useful Ovation Engineering Tools.
GeoGebra is free and multi-platform dynamic mathematics software for learning and teaching geometry, algebra, statistics, and calculus. Download the free software at http://www.geogebra.org. Find the source code at http://www.geogebra.org/trac
VisualPetri is Petri net editor for Windows platform based on GDI Plus library with an integrated simulator. Note: a Petri net is one of several mathematical representations of discrete distributed systems.