I've decided to leave IE6 behind. Couldn't resist the HTML5 / CSS3 frenzy and my customers are happy with that. I am wondering about the compatibility norms other people follow, and here are my observations :
1) 1024 x 768 appears to be a good minimum resolution for laptops/desktops.
2) Working a distinct version for mobiles, for example using jQuery mobile ( see http://solar-logos.appspot.com ), appears to be necessary. I couldn't for the love of me create portable sites using CSS media queries alone.
3) Dodging Flash and Java really IS a good idea, but not always possible, so..
4) Progressive design works well for me in most cases.
5) CSS3Pie might solve some of my backwards portability problems. See : http://css3pie.com/
Has anyone tested it?
6) I have noticed IE9 bugs that STILL echo IE6 issues (for example with file uploads, sometimes they just stall. No reason given, the file gets uploaded, but the iframe I use for Ajax uploading never gets an "onload" event back, even when working on the same domain).
Is anyone aware of that? Of this particular case? (Ajax upload with iframe, onload callback not being fired).
Of a workaround or fix?
Last but not least, what are your recipes / tips / libs for backwards compatibility? I mostly work with jQuery (latest), JSP or PHP (5.2+) on the server, Wordpress 3+ and Drupal 6+. Sometimes, I also include Facebook APIs, detection using Modernizr, and a set of jQuery plugins (doTimeout, jQuery UI, etc..).
Sorry if the questions draw on diverse technologies, it is primarily about CSS3 and relevant issues, still.
(Edited by argo_navis on 07-04-2011 15:17)