Almost all of the websites/apps uses the custom built popup (HTML) to show menu,messages,page load etc... but, some of the apps still insist on opening the same in a browser based popup window (which is annoying ofcourse).
I know both has advantage and disadvantage to each other.
So, my question is, what is the best popup method? what would be the UI experience on each of them. which one will you vote up?
(OK firefox window may not be good e.g to show but its to give an idea of traditional window :) )