I like the concept of games where one game world can be accessed through different devices. With that I mean games where you can walk through the game world on your desktop, then exit, take your mobile phone and continue there from the same gamestate as you left the game at on your desktop.
I am planning to build such a game in the future but I wonder if there are any books written on this topic?
Specifically I'd like to find out more about the following issues:
1. How to write (most) code once and get the game to work on multiple platforms.
2. What tools/frameworks are available that can help in this.
3. architectural tips for the webserver that is required to maintain the gamestate across devices.
4. Is there a common name for these types of games?
Any tips, articles, books, etc are welcome!