rfc2388
rfc2388 processes HTTP POST form data using enctype "multipart/form-data", as described in RFC 2388. Its home-page is on http://common-lisp.net/project/rfc2388/ There's another branch at the UCW repos, which is not backward compatible but contains extra patches. The main difference is that it accepts that http is a binary protocol and expects a binary network stream.

ASDF-install package (obsolete) http://common-lisp.net/project/rfc2388/rfc2388_latest.tar.gz