This tutorial presents the reasons for the renewed interest and discusses the current state of development of asynchronous design. There are many ways to design chips without clocks, so some background is offered to the various different asynchronous design methodologies used by various groups around the world today. One such style, called `micropipelines' was developed by Ivan Sutherland and formed the basis of his 1988 Turing Award Lecture. This approach has been adopted by a group at Manchester University in England and used to develop fully asynchronous implementations of the ARM 32-bit RISC microprocessor. The organization and key implementation details of these AMULET processors will be described. Finally, speculation will be offered on the future of asynchronous design techniques in a world currently dominated by clocked circuits.