I was looking at some old Intusoft newsletters from 1997 this morning, and was impressed with how in-depth and useful they were. Oddly, though, if you go to Intusoft's web site, there's a lot of information that looks like it's pretty old, and the newsletter that once came out every 2-3 months now seldom comes out more than once a year.
Meanwhile there's PSpice, which had most significant new development stopped somewhere in the acquisition chain of MicroSim->ORCAD->Cadence.
I'm starting to get the impression that, other than LTSpice, there's very little new development going with SPICE simulators today. (Even Kevin Aylward of SuperSpice fame doesn't hang out here much anymore... :-) -- and SuperSpice definitely had its own small list of really neat, unique features.) I suppose they've become mature enough that there just aren't that many more low-level features to add other than an occasional new model, but a lot of them (including LTSpice) could sure benefit from higher-level features such as Smith chart displays, the ability to use S/X/Y/Z parameter, impedance probes, automatic loop gain plots, and so on -- features available in a few packages here or there, but not at all universally. (And sadly, given LTSpice's focus, I doubt they'll ever make it to there as well -- LTSpice's graphing abilities are quite spartan compared to any of the good commercial packages... although I'm not complaining, given that the cost is $0.00.)
Oh well.
I would be interested to hear from people who've used Intusoft's ICAP/4 -- especially how it compares to, e.g., PSpice.
---Joel