IE is the most popular browser in the world right now. However, Mozilla and
FireFox have been making a BIG push recently. I like using FireFox because
it generally renders pages faster then IE. However, the memory usage is
higher, by ~3 MB, in FireFox on a Windows box. A friend made a good point on
this issue. IE is built into the OS in windows. As a result, part of it is
already running. So opening a new instance is less costly then opening a new
instance of FireFox. But, the actual footprint of IE is bigger then FireFox.
Another interesting point is the DoD or 9/11 commission (or some other
defense oriented US Gov organization) recently deemed IE a security risk and
banned internal usage.
I think this may be what you were looking for in response.