BioJava aims to provide a comprehensive set of Java components for the rapid development of applications in Bioinformatics. It contains interfaces for representing Sequences, Features, and other important bioinformatics concepts. It can also read and write sequence data in a variety of common formats and communicate with Ensembl databases and with DAS and BioCorba servers.

Bit::Vector is a (stand-alone) C library and an object-oriented Perl module (with overloaded operators) which allows you to handle bit vectors, sets (of integers), "big integer arithmetic" (e.g. for cryptography), and boolean matrices (all of arbitrary size) very efficiently.

Calc is arbitrary precision arithmetic system that uses a C-like language. It's useful as a calculator, an algorithm prototype, and as a mathematical research tool. More importantly, calc provides a machine-independent means of computation. Calc comes with a rich set of builtin mathematical and programmatic functions.

CwMtx is a library written in C++ that provides the matrix and vector operations that are used extensively in engineering and science problems. A special feature of this library is the quaternion class which implements quaternion math. Quaternions are very useful for attitude determination in 3D space because they do not suffer from singularities. Furthermore, successive rotations and transformations of vectors can be accomplished by simple quaternion multiplication. Attitude dynamics can be expressed in a very compact form using quaternions

The Date::Calc package consists of a (pure-Perl) wrapper which either loads Date::Calc::XS (a separate implementation in C and XS) or Date::Calc::PP (a pure-Perl implementation which is part of the Date::Calc package). The Date::Calc::XS and Date::Calc::PP modules perform all kinds of date calculations based on the Gregorian calendar (the one used in all Western countries today), according to relevant norms and standards: ISO/R 2015-1971, DIN 1355 and, to some extent, ISO 8601 (where applicable). The package is designed as an efficient toolbox, not a bulky ready-made application. It provides extensive documentation and examples of use, multi-language support, and special functions for business needs.

The Date::Pcalc Perl module is a direct translation of Steffen Beyer's excellent Date::Calc module from a combination of C and Perl to Perl only. The Perl module does all kinds of date calculations based on the Gregorian calendar (the one used in all western countries today), thereby complying with all relevant norms and standards: ISO/R 2015-1971, DIN 1355 and, to some extent, ISO 8601 (where applicable).

FFTW is a fast C FFT library. It includes complex, real, symmetric, multidimensional, and parallel transforms, and can handle arbitrary array sizes efficiently.It is typically faster than other freely available FFT implementations, and is even competitive with vendor-tuned libraries (benchmarks are available at the homepage). To achieve this performance, it uses novel code generation and runtime self optimization techniques (along with many other tricks).

GiNaC (GiNaC is Not a CAS (Computer Algebra System)) is a C++ library for symbolic calculations. It is designed to allow the creation of integrated systems that embed symbolic manipulations together with more established areas of computer science (like computation-intense numeric applications, graphical interfaces, etc.). Contrary to other CASes it does not try to provide extensive algebraic capabilities and a simple programming language but instead accepts a given language (C++) and extends it by a set of algebraic capabilities.

A C implementation of the DKIM message signing/verifying standard, both an API and a filter.