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.