sqlpp11 is an embedded domain-specific language which allows programming SQL very naturally in modern C++. It also enables the compiler to detect syntax errors, type errors, name errors, and even some semantic errors before they ever hit unit tests or production. Queries can be constructed at compile time or run time, offering varying levels of safety and flexibility.
cipra is a simple, TAP-compatible Unit Testing Framework for C++. It's written in 100% standard C++11 and is only a couple of header files, making it easy to include in your C++11 project. TAP, the Test Anything Protocol, is a standard output format for software unit test frameworks which was originally designed for Perl, but can serve other languages. It has a rich number of tools ("harnesses") which parse TAP-formatted output and do useful things with it. TAP, however, is equally human-readable. The name cipra (pronounced /ˈʃi.pɾaː/ "SHEE-prah") comes from the lojban phrase "lo cipra", which means "the test". It is properly written with an initial minuscule "c", even when at the start of a sentence.
SourceAFIS is a fingerprint recognition/matching SDK (library), or more generally an Automated Fingerprint Identification System (AFIS). It essentially compares two fingerprints and decides whether they belong to the same person. It can quickly search a large database of registered fingerprints. It comes with an easy-to-use API (pure .NET and Java) plus assorted applications and tools.
LibU is a multiplatform C library that comes under a BSD-style license. It includes many interdependent modules for accomplishing several tasks: memory allocation, networking and URI parsing, string manipulation, debugging, and logging in a very compact way, plus many other miscellaneous tasks. It has a small footprint (about 70KB for the default configuration), it is modular, and it has a multiplatform nature, making it an ideal candidate for embedded systems. KLone is an example of such usage.
Biomechanical ToolKit (BTK) is a cross-platform library for biomechanical analysis. It can read and write a large variety of file formats used in biomechanics, and can modify them. All these operations can be done with the C++ API or with the wrappers included (Python, Octave, and Matlab). The goal of this project is to help the community share data without the restriction of the file format or the biomecanical model provided by the manufacturer of the acquisition system.