ADODB is a set of advanced PHP database abstraction classes. It supports MySQL, PostgreSQL, Interbase/Firebird, Informix, Sybase SQL Anywhere, Oracle, MS SQL 7 and 2000, SAP DB, Sybase, DB2, FrontBase, Foxpro, Access, Netezza, LDAP, ODBTP, ADO, and generic ODBC. A metatype system is built in, making it possible to figure out that types such as CHAR, TEXT, and STRING are equivalent in different databases. It also features portable database creation, database-backed session support (with encryption), SQL performance monitoring, and database health checks.
GNU Aspell is a spell checker designed to eventually replace Ispell. It can either be used as a library or as an independent spell checker. Its main feature is that it does a superior job of suggesting possible replacements for a misspelled word than just about any other spell checker out there for the English language. Unlike Ispell, Aspell can also easily check documents in UTF-8 without having to use a special dictionary. Aspell will also do its best to respect the current locale setting. Other advantages over Ispell include support for using multiple dictionaries at once and intelligently handling personal dictionaries when more than one Aspell process is open at once.
BeeCrypt is an ongoing project to provide strong and fast cryptography in the form of a toolkit usable by commercial and open source projects. Included in the library are entropy sources, random generators, block ciphers, hash functions, message authentication codes, multiprecision integer routines, and public key primitives.
BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
BZFlag is a 3D, multiplayer, tank battle zone, capture the flag game that pits players against each other in a networked environment. It runs on Windows 95/98/NT/2000, Linux, MacOS 10.x, Irix, Solaris, and others. An OpenGL accelerator is highly recommended, but it is playable with 3D in software.
Dr. Geo is an interactive geometry program that is distributed as a universal portable application. It allows one to create a geometric sketch and manipulate it according to its constraints. It is usable at home or at school, in primary or secondary education. It is simple and effective with extended features including scripting and programming.
EO is a templates-based, ANSI-C++ compliant evolutionary computation library. It contains classes for any kind of evolutionary computation (specially genetic algorithms) you might come up to. It is component-based, so that if you don't find the class you need in it, it is very easy to subclass existing abstract or concrete class.
FLTK (pronounced "fulltick") is a cross-platform C++ GUI toolkit for UNIX/Linux (X11), Microsoft Windows, and Mac OS X. It provides modern GUI functionality without the bloat, and supports 3D graphics via OpenGL and its built-in GLUT emulation. FLTK is designed to be small and modular enough to be statically linked, and also works fine as a shared library. It also includes an excellent UI builder called FLUID that can be used to create applications in minutes.
FXPy is a Python extension module which provides an interface to the FOX cross-platform GUI library. With a few minor exceptions, FXPy provides a complete interface to FOX. FOX is a C++-based toolkit for developing graphical user interfaces easily and effectively, and it runs natively under both Unix/X and Microsoft Windows. Some of the significant features of FOX include a rich set of widgets, powerful but easy-to-use layout managers, extensive support for 3-D modeling using OpenGL or Mesa, drag-and-drop (using the XDND protocol) and a registry for persistent application settings.