The problem that you face here, is the way binaries and the web works. Compiled applications like cocoa apps will only work if at least their starting binaries are there. But this basically means that the user already has downloaded the binary.
Furthermore, these apps will create their own application preferences - so a downloaded version of Coda will have no license.
And if the user has downloaded you binaries, what will stop them from using your software forever? (Just apart form license problems with the authors of said software).
So, the only thing that you could do, is to present them with some kind of VNC like client that will grant them limited access to an environment that you have under control. But writing that is way out of scope for this site.
(I assume, that the application are not already installed locally, but be usable from the server).