I've always used IEView to view Internet Explorer-only pages on my Firefox,
but this extension seems really better than the previous. IETab
permits you to open a IE-only web page under a tab in Firefox (so no new window
opened).
To use it, just right click a link and choose "Open
this link in IE tab"... magically you'll obtain a tab where the page
works under the IE engine. Cool! 
However, I've to signal a strange thing: the first test I've done after the
extension installation (under Firefox 1.0.7) was to try to open Windows Update under a tab in Firefox.
Result? This page: 
The extension doesn't work?
No... I've opened Google, typed "Windows Update" on the search
engine and then opened the link with the "Open this link in IE Tab"
option.
Result? This:
You can easily run Windows Update without using Internet Explorer. The trick
is only to open it directly (and not by typyng the url on a IE Tab). Cool!
