Link to cross-browser documentation wikis.
We are actually working to make docs on MDN more cross-browser in general and will find other opportunities to share other useful wikis through programs and content like the new MDN Learning pages.
Hey Jedisciple. I have added a bug about this just to be safe. You can track our thoughts on this matter there:
You're definitely welcome to link to those sites from MDN as appropriate. It's great that they're wikis with a CC-BY-SA license.
As far as a browser-independent de facto authority, I'm not aware of any that are interested in providing such a resource. The W3C is, of course, definitive, but not community-generated; their Web Developer's Guide to HTML5 (http://dev.w3.org/html5/html-author) is more readable for web developers than the spec. The Web Standards Project (http://www.webstandards.org/) does great work to promote web standards (and they have a great teaching curriculum), but a documentation wiki does not seem to be on their agenda.
Mozilla's mission is to promote openness, innovation and opportunity on the web. Creating Firefox is a means to that end, but not an end in itself. We want web developers to use open web standards in preference to proprietary technologies because we think that's better for the web as a whole in the long run. So, we want to help web developers work in the real world, which includes multiple browsers.
To be honest, I was hoping for something not directly controlled by any browser vendor. I love Mozilla and the work you/they/it does, but want something independent of all parties to act as a de facto authority.
Thanks for those! I'll see how we can work them into the wiki. And thanks for the vote. :)
Marcel Korpel commented
There are more sites containing cross-browser issues. See this question on Stack Overflow to see several of them: http://stackoverflow.com/questions/2888876/resources-for-looking-up-differences-in-rendering-behavior-between-web-browsers-a