CMake is an open-source, cross-platform family of tools designed to build, test and package software.
CMake is used to control the software compilation process using simple platform and compiler independent configuration files, and generate native makefiles and workspaces that can be used in the compiler environment of your choice.
The suite of CMake tools were created by Kitware in response to the need for a powerful, cross-platform build environment for open-source projects such as ITK and VTK.

CMake allow to build multiple projects, libraries, targets … with simple scripts, with independant rules for each platform. It offers the possibility to install the project and create packages ready to be deployed on a client PC, or even to conduct unit tests.