"gadgets.realtime and the APIs built on top of it allow gadget developers to write applications that communicate asynchronously with another endpoint, whether that endpoint is another instance of the application (on another machine, or in another browser, for example), the container hosting the gadget, or an application hosted in the cloud. The obvious application of these APIs is 1:1 gaming -- at its most basic a Tic-Tac-Toe game between two users. However there are many other more complex (and arguably -- depending on your thoughts about games -- more interesting) scenarios that these APIs enable; for instance, a chat application that translates text as participants type it, or a shared whiteboard, or an application that lets a couple choose the best flight for their upcoming vacation."
For now, the APIs are only available in a developer sandbox, which includes a special interface of Gmail Chat. Here's how you can play chess with one of your friends:
* Go to the sandbox and send this link to your friend: http://talkgadget.google.com/talkgadget/sandbox .
* When your friend started to use Gmail Chat's sandbox, click on "Options", select "Start application", paste the following address:
http://code.google.com/apis/talk/examples/chess.xml
and press Enter.
If you don't know how to play chess, try two other applications:
* a very simple rock-paper-scissors game:
http://code.google.com/apis/talk/examples/rps.xml
* an automatic translation application:
http://code.google.com/apis/talk/examples/interpreter.xml
{ via Google Talk Blog. Thanks, Niranjan. }