Objectives: have a scalable system to build large software in Lisp, featuring deterministic separate compilation and enforced locally-declared dependencies.
XCVB itself is its own executable program to drive CL development from the shell command-line. However, it is distributed with a module /xcvb/master (aka :xcvb-master if loaded by asdf) that provides the functionality of compiling a system from Lisp and loading the result into the current image.
More details can be found on the XCVB page on common-lisp.net.