The LFO plugin allows for opening and saving files right off of the web server that FCKeditor is running on.
It should be noted that the LFO plugin uses a custom file browser called the LFO browser. It cannot be used with any other browser. Additionally, the browser is only written in PHP so it can only be used on systems that have PHP. The plugin and browser have only been tested on Slackware Linux with Apache.
The LFO browser is a modified version of the default browser that comes with FCKeditor. However, the file structure browser uses is quite different. This plugin as designed to allow for a loose structure that can accomodate file editing for many different projects. Simply put, all file browsing starts at a top level that you specify and users can put whatever they want wherever they want. Of course, there are restrictions on file types that you can configure.
Warning - Please understand security issues that can arise from allowing write access to your server before continuing! I designed this plugin for internal intranet use so security was not a huge concern. If you see any blatant security issues, please let me know!
Questions and ideas go to greggp@pobox.com. I'll try to answer as soon as possible.