'App' is a preprocessor for C++ that accepts as input arbitrary C++ code that may contain embedded constructs for specifying algebraic data types and associated pattern matching operations, and produces as output the same code with all such constructs translated to normal C++. What app essentially does is provide for C++ pretty much the same capabilities that functional languages have regarding algebraic types. 'Applib' is the associated runtime library that supports the core run time requirements of the translated code, and which provides additional utilities (applib is covered by the LGPL).
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.
Builder Xcessory PRO for Linux is the industry's most advanced graphical user interface builder for Motif. BX PRO provides a comprehensive visual reuse environment that speeds development of mission-critical applications. BX PRO integrates three best-of-breed tools to create an unparalleled application development suite.
"C Server Pages" is a C++ application server. It runs server pages written in HTML with C++ embedded and templates with C++ beans. It features scalability and integration with the backend, multiprocess and multithread functionality, and it is tunable, load balancing, and behaves well even when highly loaded.
Libcwd is a full-featured and well-documented library that assists C++ developers with debugging their applications. It includes support for ostream-based debug output, custom debug channels and devices, memory allocation debugging, run-time sourcefile:linenumber information, and demangled type names of variables. It is thread-safe.
ChemApp is a programming tool from the area of computational thermochemistry. It is a library consisting of a rich set of subroutines, based on the thermodynamic phase equilibrium calculation module of ChemSage. It permits the calculation of complex, multicomponent, multiphase chemical equilibria and their associated energy balances. ChemApp is available as object code for a wide range of platforms and as a shared library/DLL. ChemApp "light" is the free version of ChemApp, and although it is restricted in two ways compared to the regular version, it gives you almost the same functionality.
ClanLib is a cross-platform game SDK currently supporting Windows and Linux. It provides easy-to-use interfaces for 2D graphics, input, sound, resources, networking, GUI, OpenGL, and more. The goal is to provide a game SDK that does all the dirty work that all modern games need to implement anyway, thus making the game developer concentrate on the gameplay instead of reinventing the wheel over and over again.