For the Pocket PC part of my question I would like to point out this article proving that it can be done
http://www.wired.com/gadgets/mods/news/2005/01/66292
"To access the Mac, Teddy installed a Virtual Network Computing, or VNC, client on the handheld and a VNC server on his PowerBook at home in Vienna. VNC is a standard, open-source protocol for network computing, with client and server software for dozens of platforms, including relatively obscure machines like the Newton."
So what program do I need
some more info I dont understand:
"to screen share turn on screen sharing on the Mac and set a password. then download tightvnc on the notebook and allow it to unlock the firewall and add a password. then open tightvnc viewer and connect to your iMac's IP which is shown in network preferences and supply the password. to connect to the PC open connect to server in the Finder and type this in "vnc://PC's IP Address" and supply the password."
https://forums.macrumors.com/threads/431957/