Application Based Environment

I am starting a new project and our approach wants to be something of a mock operating system with individual applications. We develop a similar product for multiple clients and there is generally customization on an individual level for certain portions but other core areas that are unchanging. For development purposes, both on the frontend and backend we want to keep everything as independent as possible with a basic environment to run these "applications" in. So, I'm just looking for advice on how to best approach this.

Currently, frontend is done completely in VB. We have individual solutions and just copy pages over from one to the other when new components are created. Of course, everything is so integrated that a change may work properly on one version of the app but may need quite a bit of additional work on the other to integrate properly. We've found that there are only a few key pieces of information that tie all the different pages together.

The only thing that seems like it could be close to what I am looking for is XBAP applications. From what I gather, you can have an HTML wrapper and load individual XBAP's into a frame and pass data from one the the other. I have only done very basic windows application development and no WPF development so I would definitely have quite a bit to learn if this is, in fact, more along the lines of Windows Application Development. Unfortunately, there seems to be a limited amount of information out there on getting started with XBAP development.

Any advice on this situation would be greatly appreciated. Thanks in advance.