MAKR, 2007-08-01: rechan is a small Tcl extension written in C. It consists of only one C source file and strives to make reflected channels available to the Tcl 8.4 script level. Some basic information extracted from the source file:
* Written by [Matt Newman] and [Jean-Claude Wippler], as part of [Tclkit]. * March 2003 - placed in the public domain by the authors. * * Reflecting [channel] interface
As for how to use it, have a look at Rchan allows channels to be implemented in Tcl.
LV Where does one find this extension?