Tiny CLOS for R6RS Scheme.
Christian Sloma did the original conversion to R6RS. The Mosh Scheme team packaged it for Mosh. I ran into some issues in getting Sloma's original version running. So I tweaked Mosh's version to work with other implementations. The basic test program test.sps runs in Chez, Ikarus, and Ypsilon. You can load the libraries into Mosh, but the test program doesn't pass due to a bug in Mosh (thanks to David Banks for help with that).
The only dependency is surfage.
$ cd ~/scheme # Where '~/scheme' is the path to your Scheme libraries
$ git clone git://github.com/dharmatech/surfage.git
$ git clone git://github.com/dharmatech/clos.git