Chromeless requires you to write your apps in HTML5/Javascript, whereas XULRunner requires you to write your apps in XUL/Javascript. Given that HTML5 is a much

Chromeless requires you to write your apps in HTML5/Javascript, whereas XULRunner requires you to write your apps in XUL/Javascript. Given that HTML5 is a much more widely known standard than XUL, I'm glad that Mozilla is pushing forward with Chromeless and relegating XULRunner. Ideally, Chromeless would allow you to take your webapp and (with minor modifications) turn it into a desktop app or vice versa.