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.
The project page of SNAP and the provided toolboxes can be found at http://step.esa.int. There you will find tutorials about the usage of the application, a forum where you can ask questions and lots of other interesting things.
The intention of the development is to provide a platform for thematic toolboxes which support certain missions or specific domains of remote sensing. The support is not limited support researchers with tools fo analysis, but also supporting the operational use of the EO data.
The common platform is jointly developed by SkyWatch, CS-FR, CS-RO and Brockmann Consult.
How SNAP and the toolboxes can be built from source is documented in our Developer Guide.
