> If you insist on a GUI, the only real choice is Qucs. I'd agree with that wholeheartedly. Although like much Open Source SW, QUCS is a work in progress, it's already more versatile than most variants of SPICE.
In my work as an RF circuit designer, I've found it very powerful, and have almost ceased using a well known piece of RF/microwave analysis/synthesis software in favour of it. The only feature I currently miss is the ability to run harmonic balance sims. properly. In my limited experience, simulation of normal analogue and mixed analogue/digital circuitry works as well as most expensive mixed mode SPICEs and better than some of the cheap ones. It has always struck me that as the QUCS development team have the integration of schematic capture and PCB layout in their roadmap, it would be worth the Kicad development team looking to see if the two packages could be integrated. Incidentally, AFAIK SPICE isn't Open Source. Unless something has changed in the last couple of years, copyright for the core SPICE source code is held be the University of California, Berkley. Chris Bartram
