The C++ Portable Types Library (PTypes) is a simple alternative to the STL that includes multithreading and networking. It defines dynamic strings, character sets, variants, lists and other basic data types along with threads, synchronization primitives and IP sockets. It is portable across modern Unix and Windows systems and includes a sample HTTP daemon showing the full power of the library.
The CFD General Notation System (CGNS) provides a general, portable, and extensible standard for the storage and retrieval of computational fluid dynamics (CFD) analysis data. CGNS is designed to facilitate the exchange of data between sites and applications, and to help stabilize the archiving of aerodynamic data.
Lua is a great programming language that prides itself on ANSI C portability, small size, simplicity, and ease of embedding. Due to these goals, the official Lua distribution cannot provide features common to popular stand-alone scripting languages. The goal of the LuaCheia project is to make a full-featured language based on Lua that makes it more usable as a stand-alone language.
SIMD Cross-platform headers is a cross- platform, cross-compiler, cross CPU C/C++ header collection that aids the creation portable vectorized (SIMD) C/C++ code. It supports (or partially supports) x86 (MMX/SSE/SSE2) GCC and MSVC, PPC Altivec GCC and CodeWarrior, ARM GCC, and software-emulated SIMD.