ReadTheDocs: AVNI
The backend codes that are used in various applications are part of the software ecosystem called Analysis and Visualization toolkit for plaNetary Inferences (or AVNI), which provides access to tools, techniques, models and data related to global solid Earth geosciences. The documentation for the AVNI Github repository is available from this link.
Manual in PDF: AVNI
The software manual for the backend AVNI codebase is available in Portable Document Format (PDF) through this link.