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.
Elektra is a universal hierarchical configuration store, similar to GConf and the Windows Registry. It allows programs to read and save their configurations with a consistent API, and allows them to be aware of other applications' configurations, leveraging easy application integration. While architecturally similar to other OS registries, Elektra does not have most of the problems found in those implementations. Elektra includes a library, an API, and commandline and GUI tools for administration tasks.
SQLite/Ruby is a set of bindings to allow the SQLite (v 2.x) database to be used from Ruby scripts. It provides an object-oriented interface to all major functions of the SQLite API, including the create_function and create_aggregate functions. It also supports bind parameters, transactions, internal and external iterators, type translation in queries, and easy access to various pragmas.