CMUCL is a high-performance, free Common Lisp implementation for Unix platforms. Its CVS repository is hosted here at common-lisp.net, but its web presence is at www.cons.org/cmucl.
If you're just looking to download some binaries, you can go directly to common-lisp.net/project/cmucl/downloads/ to get them.
You can browse our CVS repository or download the current development tree via anonymous cvs, as described in the common-lisp.net FAQ.