This is wikipedia - wikipedia.org/wiki/ASP.NET Its a webserver application designed by microsoft and mainly for microsoft operating systems. One of the bad things, at least that I have seen is that ASP designed sites run best on a windows server OS, and with internet explorer. The company I work for, some of their servers run a few special ASP application pages. I dont know if its because of the developers or the program, but the sites will not work properly with firefox.