If you came of age in the modern cloud era (Post-2010), Telnet is that "insecure thing" you disable on routers. But for those of us who cut our teeth on BBSes, mainframes, or early Unix hacking, —a raw, text-based window into another machine.
Next time you need to debug an SMTP server or test a custom TCP service, skip nc (netcat) for an hour. Fire up a Lisp REPL, open a socket, and talk to the machine directly. You'll never look at curl the same way again. If you landed here searching for "Lisp CLOS" (Common Lisp Object System) or "Lisp TCO" (Tail Call Optimization), drop a comment below. I've got drafts on both. But if you really meant tlen as some obscure library... well, now you know how to roll your own. Happy hacking, parentheses and all. lisp tlen
I recently spent a weekend revisiting Telnet, not as a sysadmin, but as a Lisp programmer. Why? Because stripping away TLS, JSON, and REST frameworks reveals something beautiful: If you came of age in the modern