This special issue is about the methodologies and tools that may help us solve the VLSI design crisis of the 1980s. Basically, there are three approaches. The first school of thought believes that all design decisions should be made solely by the human designer, who has gained experience through good design practices in the last 10 or 20 years. This approach, called computeraided design, gives the designer an "efficient paper and pencil" by providing graphic editors, design verification and simulation tools, and efficient databases. This approach is evolutionary and tends to be bottom up, since building blocks are first designed and then later used to realize higher level structures. The resulting design is of high quality, since humans are very good in optimizing designs. On the other hand, the human designer is slow and error-prone. Furthermore, creative designers optimize design by creating new design rules, thereby creating a demand for new verification tools and design description languages for documentation and communication between designers. After a bried review of the three approaches, the collection of articles presented, depicting all three approaches to VLSI design tools (each representing a different methodology in VLSI design), are briefly summarized.