blogsym
Blogsym is a Common Lisp blog software that acts as a "blog compiler" to PHP. Blogsym creates PHP pages from special markup. PHP is only used for the comment feature, so it would be easy enough to produce plain HTML by removing the comment stuff.

The main feature of Blogsym is multilingual support; blogging in two (or more) languages at once is relatively simple. See http://ola.rinta-koski.net/blog/ for an example of a blog created with Blogsym in Finnish and English.

For better or worse, Blogsym doesn't depend on any other Lisp package, so you can run it on a vanilla CL. The development is done on OpenMCL.

Find Blogsym at http://ola.rinta-koski.net/blogsym/

Why not just use CL on the server?

Why indeed? Well, PHP is a far lower common denominator than CL when you look at a typical web server installation. Blogsym is not intended as a solution for the case when you can serve the pages directly out of CL.