[plt-scheme] Beginner-friendly Net access functions?

Stephen Bloch wrote:
> Are there any library functions for net communication that have 
> really simple interfaces, suitable for first-semester programming 
> students?  I recall somebody talking about a classroom exercise in 
> which students could send messages to one another, but now I can't 
> find that discussion in my files. 

hamsup.ss, in TeachScheme! 2 2004.

http://www.ccs.neu.edu/home/matthias/HtDP/Extended/

--PR