zRBF (Create > zRBF)
An RBF solver for Maya.
Introduction
There are a few of these, but they're all either commercial, under restrictive
licenses, or native C++ plugins. This plugin is rough, with no UI and only simple
vector-to-scalar support, but it's simple, permissively licensed, and written in
Python to simplify installation.
Some other implementations are here. I haven't tried any of these:
Limitations
Being written in Python is convenient and not a performance problem when used for
things like high-level rigging, but its performance wouldn't be suitable for things like
calculating textures or dense particle systems.