Reminds me of Maya. I had to sit down for a minute when I realize 90% of the UI is a mel Script. The core of the software is an interpreter/server for some lazy DAG. Actually I wanted to mention Maya, from its performance on piss poor[1] desktop hardware of the late 90s it was able to pull real time Rigid Body dynamics over Nurbs surface (and even pseudo Non Rigid) while staying responsive.

[1] Pentium 2 350 with a NV3 ~gpu.

Blender is great, but the UI is very non-standard (for little benefit). A good program can be used by domain experts without reading the manual, something that's not possible with Blender. 3D Max, 4D Studio, and CAD apps like CATIA have a much more intuitive UI.