puri
puri, Portable Universal Resource Identifier, is a library for parsing and representing URIs.

Current API documentation is available from Franz's Allegro CL documentation: https://franz.com/support/documentation/current/doc/uri.htm

There is a fork that extends puri to support userinfo and specialized uri classes and re-implements the parser with cl-ppcre at https://github.com/lisp/com.b9.puri.ppcre