Hi,
i have two questions:
1) was HTML5 released and if yes, when?
2) is doctype HTML 5 in use? or is it better to use one of these: - HTML 4.01 Strict, - HTML 4.01 Transitional, - HTML 4.01 Frameset, - XHTML 1.0 Strict, - XHTML 1.0 Transitional, - XHTML 1.0 Frameset, - XHTML 1.1
<!DOCTYPE html>
That's the HTML5 doctype. All modern browsers support HTML5, although feature support is not necessarily complete.
As of March 2010, the specification is in the Draft Standard state, according to the W3C timetable HTML5 should reach W3C Recommendation state by late 2010.
Nice table of HTML5 Feature support shown here: http://www.findmebyip.com/litmus/#target-selector
In my opinion, there's no reason not to use the HTML5 doctype.
A nice about this new DOCTYPE, especially, is that all current browsers (IE, FF, Opera, Safari) will look at it and switch the content into standards mode - even though they don't implement HTML5. This means that you could start writing your web pages using HTML5 today and have them last for a very, very, long time
Per a quick google search:
Question 1: yes, On January 22nd, 2008, W3C published a working draft for HTML 5. http://www.w3schools.com/w3c/w3c_html.asp
Question 2: There are a few example html 5 sites to demonstrate what it can do, though they just use <!DOCTYPE html>:
http://html5demos.com/
"Note: HTML 5 is not a W3C recommendation yet! " http://www.w3schools.com/html5/html5_reference.asp
Edit: As Marcel Korpel said... a working draft is not an official release.
You can test some of the features of HTML5 here http://html5demos.com/ HTML5 dosen't get 'released' it is a specification that will get implemented into browsers bit by bit as time goes on. Although most popular browsers have implemented most of the standard to date.
You can find the latest draft on http://whatwg.org/html5.
There's a section about HTML 5's Doctype there.