Welcome to the amazing world of Common Lisp, the programmable programming language.

This site is one among many gateways to Common Lisp. Its goal is to provide the Common Lisp community with development resources and to work as a starting point for new programmers.


Latest news

Migration has come to a close. Nearly all services are up and running again, with the exception of Arch and ArchZoom, for which support has been dropped. Here's a list of other changes:

We're moving to a new server. In the process, all services will be completely reconfigured from scratch, with each service moving to its own subdomain. This work is likely to cause service interruptions over the coming weeks. If you want to offer a helping hand, please join clo-devel at, where the process is being discussed and coordinated.

I've updated the scripts that generate the DarcsWeb repository listing. If something seems awry, please send me an e-mail.

Drew Crampsie and Gary King, both members of the Tech Co-op, have volunteered to take care of the duties required to administer We would both like to extend a hearty thanks to Erik Enge for all the hard work over the years.

Due to commitments at work I'm unable to provide adequate support to The result of which is that there are several outstanding project applications (sorry guys, hope to get to them this week) and other misc tasks. I'm looking for someone to take over the day-to-day administration of - I'll be happy to keep paying for the site and manage the donations (though equally happy to give that up as well). Email admin (at) if you are interested. The chores involves mostly a couple of shell scripts that take care of adding users and projects.

We extended the filesystem with another 5G last night which resulted in it being left in a read-only state without us noticing right away. Sorry for the inconvenience, all is well now.

While the hoster was performing a filesystem backup we experienced a failure which eventually led to a reboot. All should be fine again, apologies for the inconvenience.

Older news...


What is Common Lisp?

Common Lisp is the modern, multi-paradigm, high-performance, compiled, ANSI-standardized, most prominent (along with Scheme) descendant of the long-running family of Lisp programming languages.

Common Lisp is known for being extremely flexible, having excellent support for object oriented programming, and fast prototyping capabilities. It also sports an extremely powerful macro system that allows you to tailor the language to your application, and a flexible run-time environment that allows modification and debugging of running applications (excellent for server-side development and long-running critical software).

Common Lisp is a multi-paradigm programming language that allows you to to choose the approach and paradigm according to your application domain.

You may find more of the Common Lisp community at these resources:




About this site

If you want to request a project, read this document.

If you have questions, suggestions or comments about this site or you simply wish to reach the current maintainers, email this mailinglist.

The documentation, procedures, feature requests etc are located in our Trac instance: clo's Trac.

Be sure to read the FAQ before asking questions.

This site is paid for by the donors listed in the donate page and currently maintained by the Tech Coop.

Hosting is provided by the very capable guys over at Tech Co-op. They provide inexpensive hosting and Common Lisp pre-installed.