[plt-scheme] Networking protocols in Scheme?

Implementations of network protocol abstractions are all about details.
Two key areas of detail are resilience and performance, which are not
clear from an API spec.

I suspect that Rebol has decent protocol implementations, although the
API examples in their manual are not as robust as I'd want for most real
applications.  (They will be forgiven for the toy usage examples in
their manual, which do not seem to handle exceptional conditions like a
real application would have to.  I assume Rebol has other features that
make possible writing robust network applications.)

PLT has a similar set of networking libraries standard.  PLT also
provides a lot of low-level facilities and fancy I/O abstractions for
which I'm recently finding good use.

Examples of network applications written in PLT include the Help Desk
(which is actually a Web browser), and an email client used by some
people on this list.

I've been running a Web-scraping agent program for over a year under
PLT, and the program has been remarkably resilient in face of network
outages and peculiarities, server throttling, anti-bot detection
measures on the Web site, site HTML changes, etc.  I think that would've
been much harder to write in Java and perhaps Rebol.