Is it possible to develop a web-app in ASP.NET (framework is not a constraint), to have a sandbox architecture, and deploy widgets without disturbing the parent application?

I expect both the parent application and the widget to be developed using .NET.

EDIT: To elaborate, I want to have an web-app, say App1, and widgets (say wid1 and wid2). wid1 and wid2 should be like a plugin into App1, only difference is that, if I make any changes to wid1, I want to be able to deploy it without disturbing App1 or Wid2. The widgets can be something similar to a flash object, only that it needs to be developed on .net.