You must be my doppelganger, because I've been saying exactly this for some time. Internet Explorer caused so much trouble partly because it accepted so much bad HTML. It would close tags for you, even.
IE didn't start that, it had to accept that shit because everything else did long before it. I'm not even sure what browser started it. I'm positive that the first graphical browser I used (Cello) did, though.
I'm not even sure it was really considered a bad thing at the time.
P: Paragraph mark
The empty P element indicates a paragraph break.
The exact rendering of this (indentation,
leading, etc) is not defined here, and may be a
function of other tags, style sheets etc.
To whit, the well-formed, "good" example:
<h1>What to do</h1>
This is a one paragraph.< p >This is a second.
< P >
This is a third.
Yes, with spaces and alternating case. This was the standard before
IE6 came out, so it's not that crazy that they closed up some bold and
italics tags -- I'm not entirely sure if there were (are?) any other
SGML dialects that were quite as loosely defined as early "HTML" was.
I think IE6 did a lot of awful things, but the only real "damage" done
was in borking the CSS implementation (especially the box model). The
fact that it rendered crap HTML sort-of-ok wasn't all that bad.
It was the crazy things it did with, lets say.... specially crafted
HTML that led to a lot of problems. And MS FrontPage's insisting on
adding COLOUR="#000000" (black) to all documents, and assuming
BACKGROUND was set to white did a lot to break semantic mark-up.
Oh yeah, I'm not saying IE6 didn't do a lot wrong, just that this wasn't one of them.
But I also think it's worth remembering that IE5/6 also featured a lot of early experiments in things that are now considered essential components in the web. XMLHttpRequest was a huge advancement, and while ActiveX was obviously crappy it was at least part of an attempt at creating a more dynamic web.
The automatic tag closing behaviour is even specified now.
But look at it another way: imagine browsers accepted only valid HTML and every browser had some bugs in what they consider valid. Writing a document in a way that it displays at all might be a challenge already then. Add to that that not everyone is on the latest browser version (that was probably more true in the 90s as well) and you get all the current pains just with worse symptoms. I'm not really sure that's better.
I may be wrong here, but isn't implicit tag closing consequence of html deriving from sgml? mandatory tag closing is something that came with xml AFAIK
Yes, but then nobody implemented the SGML definition of HTML correctly. According to the standard, browsers should have parsed
<a href=foo/bar/baz>qux</a>
as
<a href="foo">bar</a>baz>qux</a>
since it did not only include optional closing tags, but also short tags. (This is incidentally why several SGML-based HTML validators used to complain about "end tag for element A which is not open" in the presence of href attributes without quotes.)
IETF groups continue to perpetuate this junk, too. It opens up security holes, as you can end up with a "confused deputy" situation. A proxy might read certain header fields one way because the spec encourages the proxy to "infer" the "meaning" of creative headers. But a server behind the proxy might interpret things differently.
