[Spivak]

This hasn't been true since before IE6. ActiveX, Flash, Silverlight, and beyond started the path of browser's being generic application hosts.

[asadotzler]

Nah, it was XHR which predates all of those plugins. ActiveX never went anywhere. Flash was good for FB games and YouTube video until browsers absorbed multimedia and animation. Silverlight was DOA in browsers. It was really IE's XHR (adopted by Mozilla in 2000) and then Mozilla's Dom Inspector and JS debuggers that started us down that path more than any of those plugins.