We need to support any widespread import/export format in order to be able to add a layer of persistence.
Comparing GraphML, GXL, TGF, GML, DGML and XGMML, GraphML seems to have a good support in other graph libraries and editors and seems sufficiently easy to implement. It's XML-based, widespread, supports mixed graphs, nested graphs and can be easily extended with custom attributes.
We need to support any widespread import/export format in order to be able to add a layer of persistence.
Comparing GraphML, GXL, TGF, GML, DGML and XGMML, GraphML seems to have a good support in other graph libraries and editors and seems sufficiently easy to implement. It's XML-based, widespread, supports mixed graphs, nested graphs and can be easily extended with custom attributes.
http://en.wikipedia.org/wiki/GraphML