The GDAL and OGR libraries are written in C and C++ and have an awesome command line interface (CLI). It is used extensively by GIS analysts and developers. On the Java side of the fence, GeoTools is an equivalent geospatial library. It contains code for reading and writing vector and raster datasets but it does not have a CLI. The GEOC project is my attempt to give GeoTools a CLI. It is written in Groovy using GeoScript which wraps GeoTools in a scripting API.