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.
WhiteDB is a fast, lightweight graph/N-tuples shared memory database library with a focus on speed, portability, and ease of use. There is no server process. Data is read and written directly from/to shared memory. No sockets are used between WhiteDB and the application program. It supports indexes (T-tree), persistence through logging and memory dumps, concurrency through locking, limited queries (conjunctive only), JSON, CSV and RDF support, Python bindings, command line utility tools, and JSON REST tools.
LibMCore is a library that provides some functions to create asynchronous or synchronous lightweight process and generic queue processing. Some other basic functions are also available to count core number, to enable the real-time scheduler, to set core affinity, or to manipulate cycle counters.