Script for HTML editing in a browser?

I'm looking for a simple PHP-based solution that pulls a whole page or
tagged snippets (something like <!-- EDITABLE>Edit me<!--
EDITABLE_OFF>) into a HTML form, allowing non-technical users to udate
pages from their browser. The only "extra" required would be a simple
password protection.

Flypage (http://www.flypage.com) does this, but at $199 it's too
expensive for the small project I need this for.

Does someone know about free or shareware solutions? I have the
impression that this shouldn't require a lot of code if you don't need
fancy site and user management ...

TIA!