Just a quick note to mention the release of CL-RCFiles 2.0. This version adds pre-loading initialization files. From the README file:
This very small Common Lisp library provides a way to add initialization files to ASDF systems. Every time ASDF loads <system>, one or several corresponding <system>.lisp files are loaded automatically afterwards. This lets you conditionally plug in additional behavior on a per-system basis without cluttering up any global Common Lisp init file.
By default, these initialization files are expected to be found in: - ~/share/common-lisp/rc/pre/ for pre-loading initialization, - ~/share/common-lisp/rc/post/ for post-loading initialization.
For backward-compatibility, files found directly in the rc/ directory are considered to be post-loading initialization files.
You can modify the rc-files location by changing the values of the global variables *directory*, *pre-directory*, and *post-directory*.
Get it here.