The library is descended from a set of geometric routines present in Inkscape, a vector graphics editor based around the Scalable Vector Graphics format, the most widespread vector graphics interchange format on the Web and a W3C Recommendation. Due to this legacy, not all parts of the API form a coherent whole (yet).
Rendering is outside the scope of this library, and it is assumed something like libcairo or similar is employed for this. 2geom concentrates on higher level algorithms and geometric computations.