Softimage|XSI : 3D animation, modeling and rendering. It was used in the film, video game and advertising industries as a tool to generate digital characters, environments and visual effects.
It has a unique user interface with some pretty awesome features.
Autodesk acquired the Softimage brand and 3D animation assets from Avid for approximately $35 million just to kill it some years later.
Edit: add info about Autodesk