Someone recently asked me if Visual Studio 2010 supports HTML 5 Intellisense. Well the answer is - not out-of-the-box but there is a tool released by Mikhail Arkhipov (Microsoft) that makes it possible (for both VS 2010 and VS 2008). Follow these steps:
Step 1: Download the HTML 5 Intellisense for Visual Studio 2010 and 2008 tool (HTML5Setup.msi) and install it.
Step 2: After the installation is over, the HTML 5 Intellisense schema gets installed in C:\Program Files\Microsoft Visual Studio 10.0\Common7\Packages\schemas\html.
Note: If Visual Studio 2010 is not installed in it’s default location (C:\Program Files\Microsoft Visual Studio 10.00), then after running the .msi, you will have to manually move the ‘html_5.xsd’ to the location where VS 2010 is installed on your machine, for the intellisense to work properly.
Step 3: Now open VS 2010 > Tools > Options > Text Editor > HTML > Validation and choose HTML 5 as the Target from the DropDown as shown below and click OK:
That’s it. Open a page and try out the HTML 5 intellisense as shown here
Note: AFAIK, this does not work in Express Editions.
You may also want to look at SVG Intellisense schema for Visual Studio 2010 and 2008