Cactus is a general, modular, parallel environment for solving systems of partial differential equations. The code has been developed over many years by a large international collaboration of numerical relativity and computational science research groups and can be used to provide a portable platform for solving any system of partial differential equations.
The pl1gcc project is an attempt to create a native PL/I compiler using the GNU Compiler Collection. PL/I is a third-generation procedural language suitable for a wide range of applications including system software, graphics, simulation, text processing, Web, and business applications.
The Standard Portable Library (SPL) is a smart pointer based, cross platform application framework. It is intended to be used instead of STL, and has an API that should be familiar to .NET and Java programmers. It includes basic types such as Date and DateTime, runtime pointer debugging, collection templates, file I/O, networking, database access, threading, and XML parsing.
Stratego/XT is a development environment for creating stand-alone transformation systems. It combines Stratego, a language for implementing transformations based on the paradigm of programmable rewriting strategies, with XT, a collection of reusable components and tools for the development of transformation systems. In general, Stratego/XT is intended for the analysis, manipulation, and generation of programs, though its features make it useful for transforming any structured documents. In practice, it has been used to build many types of transformation systems including compilers, interpreters, static analyzers, domain-specific optimizers, code generators, source code refactorers, documentation generators, and document transformers.
Tao is a software package for sound synthesis using physical models. It provides a virtual acoustic material constructed from masses and springs, which can be used as the basis for building quite complex virtual musical instruments. It comes with a synthesis language for creating and playing instruments and a C++ API for those who would like to use it as an object library.