PolarSSL is a light-weight cryptographic and SSL/TLS library written in C. PolarSSL makes it easy for developers to include cryptographic and SSL/TLS capabilities in their (embedded) applications with as little hassle as possible. Loose coupling of the components inside the library means that it is easy to separate the parts that are needed, without needing to include the total library. PolarSSL is written with embedded systems in mind and has been ported on a number of architectures, including ARM, PowerPC, MIPS, and Motorola 68000. The source is written to have very loose coupling, enabling easy integration of parts in other software projects. Very loosely coupled cryptographic algorithms for MD2, MD4, MD5, SHA1, SHA-256, SHA-512, AES, Camellia, DES, Triple DES, ARC3, and RSA are included.
SourceAFIS is a fingerprint recognition/matching SDK (library), or more generally an Automated Fingerprint Identification System (AFIS). It essentially compares two fingerprints and decides whether they belong to the same person. It can quickly search a large database of registered fingerprints. It comes with an easy-to-use API (pure .NET and Java) plus assorted applications and tools.
rgxg (ReGular eXpression Generator) is a C library and a command-line tool that generate (extended) regular expressions. It can be useful for generating expressions that match, for example, a specific number range (e.g. 0 to 31 or 00 to FF) or all addresses in a CIDR block (e.g. 192.168.0.0/24 or 2001:db8:aaaa::/64).
uterus is a codec library for financial tick data with an emphasis on market data integrity and maintainability. It comes with a set of tools to convert (mux) and print (demux) data from some sources, and to perform standard tasks like selecting instruments, creating snapshots and candles from tick data, etc. Special care is taken to provide longevity and consistence. All timestamps are internally converted to coordinated time, and price and quantity quotes are converted to a monetary datatype which doesn't suffer from rounding errors. Most importantly, meta data is stored along with the payload data in an inseparable unit, to provide self-contained and self-documenting files or network streams.