freshmeat.net: Project details for Frog
Frog is a tool for publishing and maintaining contents on a Web site. It is a rewrite of Radiant CMS and features an elegant user interface, flexible templating with layouts, snippets, and flexible page parts, a simple user management/rights system, search engine friendly URLs, password protected live administration, and support for Textile.

Another bit of software that I am somewhat interested in looking into further.