Before you make a decision on this., be sure to watch the entire John Papa course at Pluralsight on SPA ( single page HTML5 applications that use Ajax calls to modify a main page interface.) As to UI, the jqueryUI and related libaries coupled with knockout.js for binding make some many things that used to be such an agony so easy I have to believe this is the wave of the future, certainly for web apps and for desktop as intranet.

Trust me it is worth your time to spend some time with this stuff before you invest any time in webforms etc. Don't even think about developing a UI framework until you know what jquery-ui, the related grid controls, and Wijmo can do right out of the box with HTML5

>First, thank you for your message. Just to clarify, I do not want to mix and match. I will decide on either web forms or MVC and - hopefully - will stick with just one technology. But first I want to create a project in VS 2012 and create a main page of the application. I would like to use HTML5 for the main page utilizing responsive design. But now - as I type this - I realize that when creating a project in VS 2012 I have to select either ASP.NET MVC or Web Forms. So it look like before I even create a main page UI I have to make the decision on Web Forms or MVC. Is this correct?
>
>>No. The difference will be how you handle that in the code. With MVC you typical code the .cshtml page as
>>Html.ActionLink( .....) that then points back to the controller rather than a specific URL, but you could just as easily code it to be an
>>a href and point to a stpecific URL.
>>
>>But... why do you want to mix and match. Seems it would become a maintenance issue.
>>
>>>Hi,
>>>
>>>Does it matter - when creating a main page of an ASP.NET application - if the application will be using Web Forms or MVC? Here is what I mean. Typical web (database) application will have a pull-down menu at the top, toolbar below the menu, and optionally a vertical toolbar panel. The menu, toolbars will be entry points to the application features; click on this or that item/button will open the corresponding page. I have not decided if the application will be Web Forms or MVC but only want to start working on creating UI framework. Is this logical? TIA.