SNAP is the common software platform for the three Sentinel Toolboxes which are developed by the European Space Agency (ESA) for the scientific exploitation of the Sentinel-1, Sentinel-2 and Sentinel-3 missions.
This is the source code distribution of the SNAP Desktop GUI which is developed on top of the SNAP Engine (snap-engine) and is based on the NetBeans Platform. For further information read the readme.md in the SNAP Engine project