FileCMS is a Content Management System (CMS). With FileCMS the owner of a website can easily edit the content. This doesn't require any knowlegde about websites or HTML.
You can also install FileCMS for your existing websites. You install FileCMS and provide the HTML-files with the editable region tags. FileCMS will then know which parts it's allowed to edit. It doesn't matter if you made the HTML-files yourself or if they're made by software like Dreamweaver, Frontpage, Studio Webdesign, WebCreator etc.
As an Administrator you have your own logincode. This allows you to easily change the configuration, like hide certain folders, switchen on/off buttons in the Editor or changing the language.