Reppy-Channels. A fully lock-free / wait-free implementation of Reppy Channels in Common Lisp. This system not only provides for composable events, but it is also substantially (2x) faster than lock-bound implementations. It is based on an implementation of MCAS (Multiple CAS) and lock-free queues. In an SMP environment there is now little reason to use locks against shared structures. Locks frequently are too coarse and produce bottlenecks in SMP code. The lock-free / wait-free methods here allow competing threads to help other threads reach a conclusion if they have been time-sliced away and were still partway through an MCAS operation.