It's true, and it's acknowledged up-thread. All the other "IE5" releases are Trident ports, however, and I believe there are up to nine of them, depending on ho

It's true, and it's acknowledged up-thread. All the other "IE5" releases are Trident ports, however, and I believe there are up to nine of them, depending on how you count: Windows 3.1, Windows NT 3.x, Windows 95, Windows 98, Windows ME, Windows NT 4.0, Windows 2000, Solaris, and HP-UX. In addiion, as you mention, an "IE5" of different lineage is also available for both Mac OS Classic and Mac OS X. Here is another thing which may seem crazy in today's world: IE 5.01 was officially supported by Microsoft on Windows 2000 until 2010, more than 10 years after IE5.0's release!