The kind of web applications I want to build are like these examples below: (sorry, i can't post links yet) - metacalc.com - csgnetwork.com/caloriesactburned.html - digitaldutch.com/unitconverter/angle.htm My question is, how are these kind of web applications are build and what program can I use to make one?
metacalc has been written in flash (but why would you bother?) calories burned could be written in anything, that's a pretty low tech example. but PHP and HTML are all you need. The big part is knowing how to do the actual calculation. The angle converter looks like all the smarts are in javascript but it could be done with PHP and ajax too, or flash if you wanted to go overboard.