cl-vectors is a pure Common Lisp library to create, transform and render anti-aliased vectorial paths.
It can be installed using ASDF-Install. See the documentation for details.
Example of application using cl-vectors and clx:

Latest version: cl-vectors-0.1.3.tar.gz.
Preview release: cl-vectors-0.1.4a.tar.gz (it includes show-annotated-path function in doc.lisp.)
GIT repository: git://git.tuxee.net/cl-vectors (browse)
See here.
The main author is Frederic Jolliton and can be contacted by email at frederic@jolliton.com.