Yet Another Dynamic Engine (YADE) is an extensible framework that is designed with dynamic libraries in a way that it is easy to add new numerical models and objects. There are four different models: Discrete Element Method based on spheres, a second method based on tetrahedra, modelling with lattice elements, and Finite Element Method.
CONSIDEO MODELER allows you to mindmap a complex problem, analyse it qualitatively to discover levers and bottlenecks, and even to simulate it by automatically building a system dynamics model. One can integrate any external data and setup a customized management cockpit for playing out scenarios. It is useful for organizational problems, project management, financial analysis, production processes, score cards, and much more.
Cadabra is a computer algebra system designed specifically for the solution of problems encountered in field theory. It has extensive functionality for tensor polynomial simplification including multi-term symmetries, fermions and anti-commuting variables, Clifford algebras and Fierz transformations, implicit coordinate dependence, multiple index types, and many more. The input format is a subset of TeX. Both a command-line and a graphical interface are available.
pyXSD maps XML and XSD (XML Schema) files into Python, checks the XML against the schema, and transforms XML documents according to user-specified Python classes. There is a framework to make these transformation classes easy to write. The program uses a simple, pythonic, non-DOM interface with the XML tree structure.