Version Targeting: Threat or Menace?
http://alistapart.com/articles/minorthreat

Zeldman, Jeffrey
List Apart, A
2008

Abstract:

Real DOM support is a game changer. Enabled by default, it would bring many sites to their knees. That would break the web, and not in quotes. Providing IE8's greater compliance on an opt-in basis is the only way to get everyone over the scripting hump.