MacSpice simulates and analyses electronic circuits that can range in complexity from a single resistor to an integrated circuit comprising tens-of-thousands of devices. It has users who range in experience from school-age enthusiasts to retired integrated circuit designers. It is used at various universities internationally for research and teaching.

MacSpice has native support for both PowerPC and Intel architecture Apple Macintosh computers. It is derived from, and compatible with, Berkeley Spice 3f5. MacSpice incorporates many improvements to Spice 3f5 – from simple bug-fixes to entirely new commands, algorithms and solution strategies. For example: the memory leaks that affected Spice 3f4 have been cured; new algorithms have been developed to facilitate the simulation of large circuits, and to reduce simulation time; MacSpice provides a robust multi-parameter optimizer and facilities for inter-process communication with other applications.