It should work on any OS, albeit Mac OS X, Windows, or *nix. It was rather simple to bump up the version compatibility to Firefox 10*. I just downloaded the latest version of Retrofind from http://test.pluckedfromobscurity.com/firefox/retrofind.html. Then, I changed the extension from .xpi to .zip. I then unzipped the file. Then, I bumped the maxVersion to 10.* in the install .rdf file. Lastly, I compiled the contents of the folder into an .xpi file by typing(without the quotes) "7za a -tzip Retrofind_for_Firefox_10.xpi content locale skin chrome.manifest install.rdf -r -mx9" in the terminal & then pressing enter. Wa-La! A bumped up version of one of my favorite Firefox addons! Enjoy.