"traces its lineage to the S-Geometry software from Symbolics"
Unfortunately, it seems that it has slipped into oblivion since 2004. The last high profile project it was used in was one of the Lord of The Rings films...
Yeah, nichimen was a spinoff from symbolics, later turned into IZware and doomed by management. However Mirai and Nendo were softwares that revolutionized 3D workflow when it came out. It brought into the mainstream what we call now box-modeling. Bay Raitt (Gollum modeler, he is at Valve now I think) had a lot to do with it, and it was not the first software to offer such a workflow, but it was the most prominent one.
Wikipedia (http://en.wikipedia.org/wiki/Mirai_%28software%29) tells me that it
Unfortunately, it seems that it has slipped into oblivion since 2004. The last high profile project it was used in was one of the Lord of The Rings films...