The easiest way to contribute is to donate. The costs of running the site are covered by the Common Lisp Foundation.
Projects waiting for volunteers
If you would like to contribute by donating your time, please let us know (through a mail to this mailinglist, for example). There are currently a few projects that need attention, and we almost always can use a helping hand.
Two projects waiting for volunteers are
- Writing a sustainable framework for listing and finding projects
- A nicer trac project page
Also, if you have a cool idea for the site, feel free to let us know.