One of the questions that often comes up during presentations on our upcoming Visual Studio 2005 Team System, when demoing the Application Designer that's built into the Team Edition for Software Architects, is whether it's possible to create your own custom application types that can be dragged and dropped onto the Application Designer's surface.
The good news is that the answer is yes. Currently, the process involves creating the required .sdm files (SDM is a type of XML document whose schema can describe various aspects of your application (application types, resources, servers, etc.), and then using a command-line tool to compile the SDM. You then use another command-line tool to create a prototype of your application type to get it to show up in the Visual Studio 2005 toolbox.
So how do you get started? Download the SDM SDK Beta 2. Included is a help file called sdm.chm. Open that up and look for the section called How to: Create an SDM System (or you can use the Go menu with the following URL: mk:@MSITStore:C:\SdmSdk\sdm.chm::/sdm/how_to__create_an_sdm_system.htm). This section describes, including samples, the task of creating your own custom application type, which is represented in SDM as a System.