And both of them were written by Ian Braid, Alan Grayer, and Charles Lang (and others) in Cambridge. Parasolid was v1 and old school C, then they got the C++ b

And both of them were written by Ian Braid, Alan Grayer, and Charles Lang (and others) in Cambridge. Parasolid was v1 and old school C, then they got the C++ bug like many of us at the time and did ACIS as v2.