HTML5 除了新增的元素(卷标)之外，还包括许多 JavaScript API，如果没有 Intellisense 还真的不太方便，如果你已经升级到 Visual Studio 2010 SP1 的话，那已经有支持部分 HTML5 的语法，不过并不够完整，微软最近推出的 Web Standards Update for Microsoft Visual Studio 2010 SP1 扩展套件就是打算用来定期提供 Visual Studio 2010 SP1 最新版的 Web 标准更新，未来预计每三个月就会更新一次 W3C 提出的相关规格变更，也期望微软能够尽快建立市场上最好的HTML5工具，因为现在很清楚，微软将穿着HTML5的外衣，坚定地致力于网络技术。
HTML5感知包括以下几个特性支持：
更新带来许多了CSS3功能，包括：多列、圆角边框、动画、过渡和转换。Scott Hanselman的博客上发布了支持功能的完整列表。关于JavaScript，更新了关于Geolocation(地址位置)、DOM存储，包括本地和绘画存储，还有其他web API的感知和验证。
About Web Standards Update for Microsoft Visual Studio 2010 SP1
Web Standards Update provides the much wanted HTML5 & CSS3 support to Visual Studio 2010 SP1. It brings VS 2010 intellisense & validation as close to W3C specification as we could get via means of an extension. The most notable supported features by this extension are:
HTML5 – Video, Audio, Input Type, Drag & Drop, WAI-ARIA, Microdata, Schema.org
Browser API – GeoLocation & Local Storage
CSS3 – 2D Transforms, 3D Transforms, Animations, Background & Borders, Basic Box Model, Basic UI, Behavior, Color, Flexible Box Layout, Fonts, Paged Media, Hyperlink Presentation, Line, Lists, Marquee, Media Queries, Multi Column, Namespaces, Presentation Levels, Ruby, Selectors, Speech, Syntax, Template Layout, Text & Transitions. It also supports vendor specific prefixes like –ms, -webkit & -moz.
Note: This extension is created by a bunch of folks within Microsoft in their spare time. This is NOT an official Microsoft product