PSIM is described as 'For engineers who want to expand the possibilities of power electronics. PSIM is the fastest and most reliable simulation tool. Built by engineers, for engineers' and is an app in the education & reference category. There are more than 25 alternatives to PSIM for a variety of platforms, including Windows, Linux, Mac, Web-based and Android apps. The best PSIM alternative is Circuit JS, which is both free and Open Source. Other great apps like PSIM are QUCS, LTspice, SimulIDE and Pspice.