Geotechnical Engineering

Geotechnics has the thinnest free coverage here, and that is not an accident: slope stability, foundation and retaining wall software is a small professional market with almost no mature open-source projects. What does exist comes from two sources — tools developed with public funding in the US, and soil data repositories.

In practice that means you will find a soil nail wall analysis tool, groundwater models, and soil surveys with engineering properties. What you will not find is a full free replacement for the commercial slope stability and foundation packages.

So the advice in this field is different: use these tools for interim checks, for learning the method and for working with soil data — not as a substitute for the design software you put your signature on.