This wasn't as much a browser feature, but an artifact of Microsoft using the same mshtml library to power as much of the system as possible in Windows 98 (IE,

This wasn't as much a browser feature, but an artifact of Microsoft using the same mshtml library to power as much of the system as possible in Windows 98 (IE, Explorer, the Office suite, etc). If I remember correctly one of the selling features of Powerpoint at the time was the ability to export to HTML for "portable" presentations.