You all probably know that new HTML 5 standard is coming. We made a new intellisense schema that you can add to VS 2008 or VWD Express 2008 and get intellisense and validation on HTML 5 elements. Note that schema is for markup only, we do not have DOM2 update for jscript intellisense yet.

How to install the schema:

1. Download attached ZIP file.
2. Place html_5.xsd in C:\Program Files (x86)\Microsoft Visual Studio 9.0\Common7\Packages\schemas\html
3. Run either x86 or x64 reg file depending on the OS and VS/VWD flavors installed. For example, for VWD Express installed on 64-bit OS run HTML-5-Schema-Reg-x64-VWD.reg and for VS 2008 installed on 32-bit OS run HTML-5-Schema-Reg-x86.reg.
4. Restart VS
5. You can select HTML 5 in the schema dropdown and HTML 5 element attributes should appear in the Properties window.

On 32-bit OS path is C:\Program Files\Microsoft Visual Studio 9.0\Common7\Packages\schemas\html. Replace Microsoft Visual Studio 9.0 by Microsoft Visual Web Developer if you have VWD installed.

Schema is experimental and has certain limitations. For example, VS 2008 and VWD are not able to validate 'wildcard' attribute names, like HTML 5 data-* attributes and is not able to handle 'transparent' content model when element content is defined by the element parent (see, for example, A element). However, it may help you to start playing with the new standard.

Mikhail Arkhipov, http://blogs.msdn.com