We refer interested users to CNApy (CellNetAnalyzer for Python), which is a cross-platform desktop application written in Python for constraint-based analysis of metabolic networks. While the basic look-and-feel of CNApy is similar to the CellNetAnalyzer user interface, it provides a more advanced graphical front-end with enhanced GUI features for metabolic modeling.
Small packages/tools working in concert with CellNetAnalyzer (used in different publications) can be found here and at the github repository of our group.
Other related packages: