That’s the reason for the vast versions of SPICE available now decades after the original was released, not all of which are as open or free as we might like. Qucs is a GPL circuit simulator.

We were interested in [Lee Teschler]’s review earlier this year of 30 free circuit simulators. If you are selecting one or don’t like the one you are currently using, it is well worth the time ...

“PICLS Lite is an incredibly simple to use free thermal simulation tool for electronic circuit boards, produced by the team behind leading electronics thermal simulation software, Cradle CFD. It ...