How can you implement a remote application with permission sharing?

Question

Windows

The essence of the problem is as follows. There is an application written on WinFroms (C#). It is necessary to somehow create such a configuration so that the application runs constantly (on the server) and at the same time users from remote computers can connect to it (with the entry of account data) and see the same screen that is displayed on the server. At the same time, it should be possible to control from within the application that only one user can perform actions at a certain point in time, but their result should be displayed on all screens. The application code can be changed.
I tried the Windows Server + RemoteApp configuration, but there the problem is that a new instance of the program was launched on each connection (if multiple connections were allowed), or when a new connection was made, the program disappeared from the screen of the previous connected user (if a single connection was allowed). Perhaps this can be fixed, but I do not know where to dig. Documentation issues.
Thus, any proposals are required that can help solve this problem (working the application in remote mode and the ability to connect several users to it with control over their actions inside the application). Even the weirdest ones. The main criterion for the admissibility of a variant in this case is that one does not have to completely rewrite the original program.

Answer 1

What is the restriction on the use of RDP?
VNC-like services would perfectly cope with your task - one subscriber connects with view and input rights, the rest - only view.

Answer 2

WCF Services Should Help