Summary of the paper “The Graph Grammar Library – a generic framework for chemical graph rewrite systems” by Flamm et al.
The paper explains how a C++ package works, which implements graph grammar rewriting rules for chemical reaction networks. There are some other chem(o)informatics stuff in the package as well.
The main story of the paper is that Yadav et al. requested a package like GGL, which is now available.
Most of it seems quite logical/intuitive based on the what it tries to do.
The software translates to/from SMILES at the beginning and end, but everything is done using graphs.
For more information and guides on how to use the software, see: http://www.tbi.univie.ac.at/software/GGL/