web application launcher

My name is jawad i am computer software Student at UET .I have an
idea which i want to implement as a final year project..the Idea is to
develop application that reside on server.when user request to server
,according to request appropriate application loaded dynamically in the

client machine in o.s environment.

we have an example of applet,but it runs under another application
which is browser.


My Idea is to develop architectuer for programmers to develop such
type of applications .For this purpose some sort of run time
environment
is required which runs appliction lanched from server.
I use Visual C as development tool.
but the question,how i plug this application in the run time
environment.
1).if appliction is in form of Executables
2).if it is in form of dlls.
3)or some other technique will be used..
4).is this type of project is already developed in Visual C.or not

Need some help to clear these points.