OpenGL Mathematics (GLM)
Google's software suite for combinatorial optimization
The Computational Geometry Algorithms Library
Computational geometry and spatial indexing on the sphere
CUDA Templates for Linear Algebra Subroutines
Matlab toolbox for Geometry Processing
C++ library for half precision floating point arithmetics.
fast C++ library for linear algebra & scientific computing
General Mission Analysis Tool
2D & 3D TeX-Aware Vector Graphics Language
Open source finite element software for multiphysical problems
For exploring cellular automata like Conway's Game of Life.
Numerical and Symbolic Math Tool
statistical tests & psuedo- random number generators (RNGs, PRNGs)
System dynamics program with additional features for economics
Android, UIQ 3.0, Series 60 Edition 5 open-source software
MathMod is a mathematical modeling software
Data Visualization and Analysis
Social Network Analysis and Visualization software
MCPower — simple Monte Carlo power analysis for complex models