Facile, integrated and comprehensive software is needed for the design of processes, models and simulation, which are required for effective production of MEMS and microsystems. The characteristics of computer-aided design software now available from seven companies are reviewed. Three of the firms have roots in microelectronics, and three were formed specifically for MEMS design. Electronic, mechanical, thermal and fluidic mechanisms are commonly included. One company is especially strong in microfluidics. Two of the design suites permit computational coupling between a MEMS device and its package. High spatial- and temporal- resolution optical diagnostics are now producing detailed data that will challenge design and simulation software for MEMS and microsystems. Near and far term prospects for the CAD of MEMS and microsystems are projected.