Luminotes makes heavy use of a browser feature called DesignMode to implement WYSIWYG wiki editing. Unfortunately, DesignMode support is incomplete in some browsers, so not all web browsers are supported.
Please note that since DesignMode is only used when you're editing a wiki, you don't have to worry about DesignMode compatability when you're in read-only mode and just viewing a wiki. So Luminotes should work in read-only mode with just about any modern browser with support for JavaScript, cookies, and remote scripting.