As the web gallery will be seen by everybody, it's evidently compatible on all web browsers from the different exploitation systems, as the Flash 9 or more plugin is installed.
The admin panel is only fully-compatible with browsers Apple Safari, Mozilla Firefox and Google Chrome. Internet Explorer 7 is also usable but strongly unrecommended because he is very slow to interpret code, and so all operations are difficult to do.
Flash 9 is required to upload photos from the admin panel. FTP and Flickr import don't required Flash installed.