That's an interesting criterion, but there are plenty of "traditional" desktop apps who keep data server side (any thin-client DB program using ODBC, subversion

That's an interesting criterion, but there are plenty of "traditional" desktop apps who keep data server side (any thin-client DB program using ODBC, subversion clients, etc). Even IMAP email clients I suppose. So is a web app "something which keeps primary data on a server, and uses the HTTP protocol to read+write it"?