(a bit of fact here):
Internet Explorer was traditionally the
vehicle for
Microsoft to release small non-critical "
service packs" to
windows. Most service packs fixed a few
bugs and added more
windows common controls (see
commctrl.h in the
Microsoft Platform SDK, or
MSDN). That is why a lot of programs "Require IE 3.x, 4.0, 5.0 or higher". It's because they added common controls to the mix that did not originally ship with Windows, but
IE required and thus implemented. Active Desktop was first introduces in
IE 4.0.
Of course, there was that whole lawsuit again, and since the new prevailing strategy from the Redmond camp seems to be to go with NT, who are used to more traditional service packs, that upgrade
vehicle seems to be at it's end.
Another interesting
technical note here is that newer
versions (IE 4.0 and up) of Windows Internet Explorer are just a sleek
COM object. That is why it runs so fast. Inside of lots of ad bars (such as
Alladvantage.com, and the free internet service provicer
1stup.com), is really an internet explorer engine object, displaying the page/banner code. It's really quite a nice system. Presumably all of IE is a
stub executable that has an address bar, and preferences, that calls an IE control (COM interface) with the right methods. I think that the object name is IWEBBROWSE. You can find this out by looking through the Object viewer that comes with
visual studio.
Also, the
Macintosh version of the
browser is based on an engine known as
Tasman; made completely differently but still quite compatable with the Windows version. This is unlike Netscape, which shares the same cross-platform codebase. They did release a version of IE for
solaris, but i heard that the quality was quite low.