Postel's principle: "be conservative in what you do, be liberal
in what you accept from others" was doctrine in early HTML
specs, and led to disastrous disagreement among browsers'
interpretation of web pages. Sadly, the "principle" lives on
despite its having been expunged from the HTML spec.
I think this is a bit unfair.
Postel was working in an environment where he was fighting an uphill battle to get the Internet going and, perhaps more importantly, taken seriously: I still vividly remember the derision that was heaped on it as a "research toy" and how the "real" implementation was going to sweep it away, usually in the form of ISO/OSI. An argument can be made that the Internet's installed base and the fact that it largely worked despite imperfect implementations headed off that particular trainwreck. Indeed, one wonders if it would have even been viable as a research project had the early ARPAnet and Internet implementors taken a hard stance on correctness.
That said, the HTML thing has always felt like a debacle to me, right from the beginning. It was an anaemic language delivered over a ridiculously bad protocol (HTTP 0.9 or whatever).I fully confess that I completely missed the World Wide Web thing when it first arrived on the scene. To my TeX and troff trained eyes used to interactive protocols, I couldn't see the point. Boy was I wrong!
- Dan C.