Flashblog is an open source php/Flash Content Management System geared towards blogging, though it could be used for any simple Flash website. The admin interface is done in PHP while the entire front-end is Flash.

The web interface is very simple to modify. There is a single Flash file that contains all the assets needed. Customizing the site is fairly simple as well--as long as you're familar with Flash, it's just a matter of drawing and moving things around where you'd like to place them. No HTML coding needed.

There are a couple downsides--for one, it's all in Spanish--unless you speak some Spanish it might be a little difficult to get installed the first time around. The second is that it's been quite some time since the site was updated, indiciating that development has, in all likelyhood, stopped--at least for now.

One of the most compelling things about Flashblog is that it could be used as a template for any Flash/PHP website. You have the .fla, the ActionScript and PHP all there for you--once you're able to understand that code, you're well on your way to creating your own customized content management system.

While it's definitely a shame that it's not under active development, it's a great open source project that is being used on several live websites.