The National Space Science Data Center's (NSSDC) Common Data Format (CDF) is a self-describing data abstraction for the storage and manipulation of multidimensional data in a platform- and discipline-independent fashion. It consists of a scientific data management package (known as the "CDF Library") that allows programmers and application developers to manage and manipulate scalar, vector, and multi-dimensional data arrays.
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.
The NCBI C++ Toolkit provides portable libraries and applications for assisting genetic science. These include libraries for networking, SQL and BerkeleyDB access, CGI and HTML handling, ASN.1 and XML handling, sequence alignment engines, sequence retrieval engines, BLAST database engines, FLTK and OpenGL graphics toolkits, and basic system utilities.
Brace is a dialect of C that looks like Python. It has coroutines, hygenic macros, header generation, and libraries with graphics and sound. It is meant to be good for beginners, kids, and experts. Brace is translated to C, then compiled, with #! support and cached executables. It is fairly portable, and runs on GNU/Linux, Unix, and Windows with MinGW. It should also run on Mac OS X. It comes with a lot of demo programs, many with animated graphics.
Easylzma is a C library and command line tools for LZMA compression and decompression. It uses Igor Pavlov's reference implementation and SDK. It is meant to be a tiny wrapper and portable build system around a subset of Igor Pavlov's LZMA compression and decompression implementation. The API is small and intended to be straightforward. The project aims to support multiple different prominent LZMA file formats and is focused on producing something that is easy to build and use everywhere.
The HLA Standard Library was developed to support the High Level Assembler (HLA), but could be used with other assemblers or higher-level languages if the necessary headers were developed. It supports 32-bit versions of Windows, Linux, Mac OS X, and FreeBSD, and is written entirely in HLA. It includes the following modules: args, arrays, bits, chars, console, conversions, cset, date, environment, exceptions, file class, file I/O, filesys, lists, math, memory-mapped files, patterns, RNG, stderr, stdin, stdout, strings, tables, time, timer, zstrings, sockets, threads, and blob. An automated test suite is included.
Real-Time Control Systems Library contains a mix of software found to be useful in the development of real-time control systems at the National Institute of Standards and Technology. It includes the Neutral Messaging Language (NML), which is used for simple configurable communications for both Java and C++ applications on a variety of operating systems. It also includes classes for converting between various coordinate systems (collectively called posemath), some XML parsing and generating tools, an .ini file reader, a timer interface, and more.