A rather important development in the world of HTML5 has taken place. The two groups responsible for the development of HTML (the Web Hypertext Application Technology Working Group or WHATWG and the World Wide Web Consortium or W3C) have decided to have two versions of HTML5 - the snapshot and the living standard - making the decision on which is best to use a rather confusing one to say the least.
Since 2004, the WHATWG has been responsible for the advancement of HTML5 but there seems to be some strife among it and the W3C. In a recent post to the WHATWG list, the editor of its HTML5 specification writes:
"More recently, the goals of the W3C and the WHATWG on the HTML front have diverged a bit as well. The WHATWG effort is focused on developing the canonical description of HTML and related technologies, meaning fixing bugs as we find them adding new features as they become necessary and viable, and generally tracking implementations. The W3C effort, meanwhile, is now focused on creating a snapshot developed according to the venerable W3C process. This led to the chairs of the W3C HTML working group and myself deciding to split the work into two, with a different person responsible for editing the W3C HTML5, canvas, and microdata specifications than is editing the WHATWG specification."
Does that mean that there will be two HTML5 standards? The likely answer, at least in the short term, is yes. The W3C is apparently planning to create a single, definitive standard (the snapshot) while the WHATWG's living standard will continue to add new features and receive refinements.
What this means for Web professionals (designers and developers) in particular is that they will, at least for the time being, be forced to choose between the snapshot or the living standard. If you want to play it safe, use the W3C's snapshot. If you want to test the limits, use the WHATWG's living standard.