Freedomeditor basic requirements:

- Webserver with PHP 5++. (If you just want to use the software on your own home windows machine, try Xamp from www.apachefriends.org, it will set you up in a second, in older versions you need to disable the officialy deprecated magic quotes in php.ini). If you are not developing on a local machine then make sure noone else can access the development environment core client, or (files in) it's folder. If you won't, you will get exotic problems caused by exotic attacks.
- Firefox Browser (adviced atleast firefox 3, with web developer and firebug plugins). (No offense to any other browsers). For extensive developing, (win)grep can be useful at times. wingrep

Freedomeditor optional requirements:

- Fontforge for alot of font conversion support
- Zend framework for phplivedocX doc(x)-rtf-txd conversion support
- Antiword + ps2pdf for .doc to .ps (postscript) to .pdf conversion support (note that antiword is 2004 software therefore might not work correctly/at all with .doc files from more recent Word versions)
- php_fileinfo.dll enabled in php.ini, for structure > file view / download