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.
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
f2py is a command line tool for binding Python and Fortran code. It scans Fortran 77/90/95 code and generates a Python C/API module that makes it possible to call Fortran routines and to access Fortran data (COMMON blocks and Module data) from Python. No Fortran or C expertise is required for using this tool.
Grok is a library of Java components for performing various natural language tasks. These include several preprocessing tasks, chart parsing, a large categorial grammar for English (induced from the Penn treebank), and some knowledge representation components (basic coreference, salience tracking, etc.). The library also has a companion kit which provides a GUI interface to the components, several of which are implementations of interfaces in the Quipu OpenNLP API.
Hodie prints the current date and time to stdout in Roman numerals, with grammatically correct Latin. Complete with Id., Kal., Non., pridie, postridie, bis, and all the other nice annoyances. As an option, it even provides you with current date according to Roman calendar -- that is 'ab urbe condita'; after Rome was built.
JavaWeather is multithreaded Java code which connects to the NWS servers to download current weather conditions and forecasts from 3,000 observation stations around the US and the world, and provide bean-like access info for Java applications and servlets (not applets). It also includes some temperature utilities.