SIS is a Java language library for developing geospatial applications. The library is an implementation of GeoAPI 3.0.2 interfaces and can be used for desktop or server applications. Apache SIS provides data structures for geographic features and associated metadata along with methods to manipulate those data structures. The SIS metadata module forms the base of the library and enables the creation of metadata objects which comply with the ISO 19115 international standard. The SIS referencing module enable the construction of geodetic data structures for geospatial referencing as defined by ISO 19111 standard, along with the associated operations which enable the transformation of coordinates between different reference systems. The SIS storage modules provide a common approach to the reading and writing of metadata, features and coverages applicable to simple imagery as to many dimensional data structures.