libxmp is a module player library which supports many mainstream and obscure module formats, including Protracker MOD, Scream Tracker III S3M, and Impulse Tracker IT. Possible applications for libxmp include standalone module players, module player plugins for other players, module information extractors, background music replayers for games and other applications, module-to-mp3 converters, etc.
TIXI is a fast and simple XML interface library for applications written in C, C++, Fortran, Java, and Python. Although simplified and somewhat restricted compared to a fully-fledged XML processing library, it can create documents, create and delete nodes, and add and remove element attributes. Routines for reading and writing text nodes and nodes holding integer and floating point numbers are included, along with routines that process aggregates of these simple types for the processing of geometric data, multidimensional arrays, or arrays of vectors.
AS3WavSound allows you to embed wav files into your project compiled with the open source Flash SDK compiler. Normally this is not possible and circumvented either by: using a licensed expensive editor that does this for you, or by the very ugly .swf workaround. This library does it natively and cleanly.
LibAPCNIS is a PHP library for accessing the NIS port of the Apcupsd UPS Monitoring daemon. It allows you to access realtime UPS stats from a PHP script without having Apcupsd installed. It does not require the apcaccess application included with an Apcupsd installation, and there are no external dependencies.
EO is a template-based, ANSI-C++ evolutionary computation library that helps you to write your own stochastic optimization algorithms quickly. Evolutionary algorithms form a family of algorithms inspired by the theory of evolution, and solve various problems. They evolve a set of solutions to a given problem in order to produce the best results. These are stochastic algorithms because they iteratively use random processes. The vast majority of these methods are used to solve optimization problems, and may be also called "metaheuristics". They are also ranked among computational intelligence methods, a domain close to artificial intelligence. With the help of EO, you can easily design evolutionary algorithms that will find solutions to virtually all kind of hard optimization problems, from continuous to combinatorial ones.