It was developed on LispWorks, but can be used with several other Common Lisp implementations as well.
It's written by Edi Weitz and can be found at http://weitz.de/drakma/.
ASDF-install package (obsolete) http://weitz.de/files/drakma.tar.gz
Drakma
Drakma is a fully-featured Common Lisp HTTP client library that knows how to handle HTTP/1.1
chunking, persistent connections, re-usable sockets, SSL, continuable
uploads, cookies, and other things.