Does anyone know how to make code online editable?

I have this webhost that has an online editor available for all files, via a file browser.

Since I have other hosts that lack this "feature" I am curious as to how one would go about making this possible, not necessarily only for PHPFusion, but since I need it for a PHPFusion site, well, any one got any ideas?

I need it for online editing of the language files, many small changes, many small updates, and I really do not see the need to neither change host, nor be connected via ftp every time I stumble over a small change I want to do. I realize this may potentially be a security issue, but it all comes down to me willing to have it, and the security I am willing to implement via, say .htaccess.

I imagine this could work as Geshi or something in a folder that reads files in predefined folder and present their content. Access to the script could easily be accomplished vi htaccess, as mentioned.

COME ON, YOU BRILLIANT FUSIONEERS! B)