SPICE is an acronym for "Simulation Program with Integrated Circuit Emphasis". It was originally developed using mainframe computers.
It's sort of a generic name now.
There are many circuit simulators using PSpice (the P means that it runs on a personal computer).
Linear Technology's LTSpice is good and free. Google is your friend here.
Texas Instruments offers Tina TI for a free download. Some like that interface better.