Magic is a VLSI layout tool originally written by John Ousterhout at UC Berkeley during the 1980s. Magic continues to be popular because it is free (Berkeley open-source license), easy to use, and easy to expand for specialized tasks. The current version is 7.1, but 6.x is still widely used.
Magic features real-time design rule checking, something that costly commerical VLSI design software packages don't feature. Magic implements this by counting distance using Manhattan distance rather than Euclidean distance, which is much faster to compute.
Magic currently runs under Linux, although versions exist for DOS, OS/2, and other operating systems. Magic is frequently used in conjunction with irsim and other simulation programs.
