TouchDesigner. It’s a cousin of Houdini, forked from a common program many years ago. It’s hooked up with nodal operators, and scripted in Python.
It’s pretty cool because you can read from an external Python file, so you can do your development in whatever IDE you want. And you can script things like procedural geometry and UVs and you can also do a lot of familiar things like compositing in a more familiar node-based system when required. It also uses GLSL for shaders, but that’s a different language. Though Processing supports it too, so your knowledge (and tutorials) would transfer across.
People are also doing some wild things in Blender which can be scripted in Python. https://twitter.com/hashtag/nodevember?src=hashtag_click
I used to also tinker in NodeBox 3, but that felt a lot more limited compared to something like TouchDesigner.