QuantLib is a cross-platform, quantitative finance C++ library for modeling, pricing, trading, and risk management in real-life. It is also wrapped as Python/Ruby/Scheme modules. Extensions for Excel, R, and Mathematica are available. Other such extensions are under consideration. QuantLib offers tools that are useful both for practical implementation and for advanced modeling. It features market conventions, yield curve models, solvers, PDEs, Monte Carlo (low-discrepancy included), exotic options, VAR, and so on.
LAM/MPI is an implementation of the Message Passing Interface (MPI) parallel standard that is especially friendly to clusters. It includes a persistent runtime environment for parallel programs, support for all of MPI-1, and a good chunk of MPI-2, such as all of the dynamic functions, one-way communication, C++ bindings, and MPI-IO.
HSQLDB (HyperSQL DataBase) is an SQL relational database engine written in Java. It supports nearly full ANSI-92 SQL and SQL:2008 enhancements. It is a small, fast multithreaded, and transactional database engine which offers in-memory and disk-based tables and supports embedded and server modes.
Contiki is an open source, highly portable, networked, multi-tasking operating system for the Internet of Things. Contiki includes a multitasking kernel, a TCP/IP stack and a set of application programs, and a low-power radio communication stack. It is written in C and designed to be very small: it runs comfortably in a few kilobytes of RAM.
ID3 mass tagger is a portable command-line mass tagger for audio files. It is designed for non-interactively adding, removing, or updating meta-information in a number of files with a single command. It can generate tag fields from the filename and rename files using an intuitive syntax. It currently supports ID3 (1.1), Lyrics3 (2.0), and ID3v2 (2.0 and 3.0) tags.