The Click Modular Router Project I have just learned of Click, the modular router. It presents a style of processing of streams that is reminiscent of a scheme designed but not implemented for Tymnet. That scheme dealt with character streams instead of packet streams and was intended to deal with individual circuit flows. The Click technology shows the utility of composeable elements in a packet environment. The one idea that our technology might have to add is freedom from stack discipline. The invention of continuations in languages such as Scheme provides an escape from stack discipline which allows the flexibility of machine language. Our style of streams avoided the stack altogether and in so doing avoids Click's distinction between push and pull elements.

The click strategy addresses the issue of scheduling. We do not, but adhoc solutions are not difficult.