I have been developing websites commercially for about 5 years now and it sickened me when I had to add IE6 compatibility on some websites because it was requested to have that compatibility. You can get the layout to look mostly like how you want it to but the functionality is greatly degraded. You might be able to design an entire site around javascript but that would not only be hell but it would destroy the purpose of adding IE6 compatibility as those who still uses that browser (the few) won't have javascript enabled because it's all business. I'm sure there are those who don't know any better but they were usually never our target audience to begin with, at least on paper. Some clients were cool and didn't care to support IE6 and you definitively come across programmers that feel obligated to support it and that you're breaking a commandment if you don't. Honestly? It all depends on who you're target audience is. Already you have to add IE 7, 8 and 9 compatibility and they all handle things differently, and sometimes you might have to do subversion support as well, then there's firefox, opera, safari, chrome, etc... But for the most part, you can make it universally compatible if you program for firefox. You'll encounter song transparency errors and maybe things will be off by a pixel or three on occasion but thankfully it's not as bad as like IE handles things. If you program correctly, you might be able to get 4/5 browsers to work just fine, if you have to adjust things, you'll need to create a javascript file that detects the browser agent and send them to the correct css file. It's a true pain but that's what programmers have to deal with when there's not a single standard for every release. The w3c is a guide, not a standard unfortunately =/