commonc++ is a C++ class library for developing cross-platform systems software for POSIX systems (GNU/Linux, Mac OS X, Solaris) and Windows (Visual Studio or GNU toolchain via MinGW). It provides C++ wrappers for common operating system facilities like threads, mutexes, semaphores, sockets, shared memory, regular expressions, filesystem access, etc., as well as abstractions for strings, buffers, object pools, timers, logging, and more.

commonc++ actually consists of four libraries: the core library (commonc++), an extension library for interfacing with a Java Virtual Machine (commonc++jvm), an extension library for embedding SQL databases (commonc++db), and an extension library for simple XML document manipulation (commonc++xml).