GF2X: a C/C++ software package containing routines for fast arithmetic in GF(2)[x] (multiplication, squaring, GCD) and searching for irreducible/primitive trinomials.
LinBox: C++ template library for exact, high-performance linear algebra computation with dense, sparse, and structured matrices over the integers and over finite fields
M4RI: A library for fast arithmetic with dense matrices over GF(2)
M4RI(e): A library for fast arithmetic with dense matrices over GF(2^e)
matplotlib: Python plotting library which produces publication quality figures in a variety of hardcopy formats and interactive environments across platforms
Maxima: System for manipulating symbolic and numerical expressions
Mercurial: Free, distributed source control management tool
MPFI: Multiple precision interval arithmetic library based on MPFR
MPFR: C library for multiple-precision floating-point computations with correct rounding
mpmath: Pure Python library for multiprecision floating-point arithmetic
mwrank: Program for computing Mordell-Weil groups of elliptic curves over Q via 2-descent. Since November 2007 mwrank has formed part of the eclib package
ncurses: a library of functions that manage an application's display on character-cell terminals (e.g., VT100)
NetworkX: Python package for the creation, manipulation, and study of the structure, dynamics, and functions of complex networks
polytopes_db: Reflexive Polytopes Databases that include lists of 2- and 3-dimensional reflexive polytopes
PPL: The Parma Polyhedra Library (PPL) provides numerical abstractions especially targeted at applications in the field of analysis and verification of complex systems.
RPy2: provides a low-level interface to R, a proposed high-level interface, including wrappers to graphical libraries, as well as R-like structures and functions.
SageMathTeX: The SageTeX package allows you to embed code, results of computations, and plots from the SageMath mathematics software suite into LaTeX documents
Singular: Computer algebra system for polynomial computations, with special emphasis on commutative and non-commutative algebra, algebraic geometry, and singularity theory
Sphinx: A tool that makes it easy to create intelligent and beautiful documentation
SQLAlchemy: Python SQL toolkit and Object Relational Mapper that gives application developers the full power and flexibility of SQL
SQLite: Software library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine
Symmetrica: Collection of C routines for representation theory
SYMPOW: Package to compute special values of symmetric power elliptic curve L-functions