What web browser engine, version, and capabilities are used to display web pages inside Visual Studio 2010?

My company is developing a plugin/add-on for Visual Studio 2010. When the user asks to display the help for our product, we plan on opening an 开发者_运维知识库HTML page (or suite of pages) within Visual Studio. I'm helping to design and implement the help system.

1. What web engine/version is used within Visual Studio 2010? According to Wikipedia it is not Trident(!).
   • _{navigator.userAgent reports: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; OfficeLiveConnector.1.4; OfficeLivePatch.1.3; .NET4.0C; .NET4.0E)}
2. Am I allowed to load remote JavaScript content (via a <script> element)?
3. Am I allowed to use XHR to load remote content?
4. Will my page be trusted and have access to the FileSystemObject?

I would appreciate any resources you can give me on programming specifically to the 'web' capabilities of VisualStudio2010-as-a-browser.

From a 2007 blog by Microsoft's Rob Mauceri, it seems that Microsoft has developed a new layout engine for development purposes:

SharePoint Designer, Expression Web, and the next version of Visual Studio's Visual Web Designer (code name Orcas) all use the same stanards-based web design component. This component was developed jointly by the three product teams for high fidelity rendering of web standards like CSS, XHTML, as well as ASP.net.

This was about Visual Studio 2008, but my guess is that it will be the same for 2010.