Microsoft invented AJAX specifically for Outlook Web Access so yes that is in fact the first "modern" web application. As I recall there was a fight about gett

Microsoft invented AJAX specifically for Outlook Web Access so yes that is in fact the first "modern" web application. As I recall there was a fight about getting it in and the creators called it XMLHttpRequest because XML was the hotness at the time and that got it past the project managers and PHBs.