To address your first point, GitHub are already doing some of this: they reduced server loads by lazy-loading commit data when cached data isn't available. htt

To address your first point, GitHub are already doing some of this: they reduced server loads by lazy-loading commit data when cached data isn't available. http://github.com/blog/293-while-you-were-sleeping http://github.com/blog/293-while-you-were-sleeping At work we do a fair amount of client-side form validation. While we have server-side validation too, doing it in the browser as well vastly reduces the number of times invalid inputs make it through to the server and have to be expensively processed. Of course, this creates other problems (making sure the client- and server-side validation routines precisely mirror one another, for example), but for some use-cases it's worth it.