In Sitefinity, when editing a page if you click properties you can enter extra page URLs.

Add a new URL something like "~/home.html" and click Save Changes.

Then Make all html pages run as though Asp.Net pages. Look here.

http://dotnetnotes.i-do-it.com/2009/11/28/MapHTMLPagesThrougthASPNETDllRunHtmlPagesWithAspnetisapidll.aspx


Then add this to the Global.Asax

 void Application_Error(object sender, EventArgs e) 
    {        
//Redirect missing Old html Pages to the default url of that page. Add Additional Urls to pages in sitefinity to redirect to those pages.
        Exception lastException = this.Server.GetLastError();
        if (lastException is HttpException)
        {
            HttpException httpException = (HttpException)lastException;
            if (httpException.GetHttpCode() == 404)
            {
                // get the name of the requested page - just the /thisPage.htm or /DIR/thisPage.asp etc
                string pageName = string.Concat("~", Request.Url.AbsolutePath.ToString());

                // create a new instance of CmsManager
                Telerik.Cms.CmsManager cmsManager = new Telerik.Cms.CmsManager();

                // let's get the page by passing one of it's additional url's
                Telerik.Cms.IPage myPage = cmsManager.GetPageByAdditionalUrl(pageName);

                // we can cast myPage as ICmsPage and redirect to the Default URL
                if (myPage != null)
                {
                    //If there isa default page then redirect to it.                    
                    this.Server.ClearError();                    
                    Response.Redirect(((Telerik.Cms.ICmsPage)myPage).DefaultUrl.Url);
                }
            }
        }
    }

Set “pageExtension” to nothing to tell SiteFInity to use Extension less URLs.

The line to change looks like this:

<cms defaultProvider="Sitefinity" pageExtension=".aspx" disabled="false" pageEditorUIMode="Overlay">

Change  it so that the pageExtension property is empty liek this: pageExtension=""

Note: The FormsAthentication and RoleManager modules are not available for extensionless request but you need them for the admin section of Sitefinity.

To enable FormsAthentication and RoleManager add the runAllManagedModulesForAllRequests property to the modules section of the Web.Config file.
E.G. <modules runAllManagedModulesForAllRequests="true">

Now you should have Extension less URLs in Sitefinity.