8. A method implemented in a computer, comprising: registering each of a plurality of application grammars, wherein registering an application grammar includes determining whether a command in the application grammar conflicts with a command in another grammar registered in the computer; receiving input including at least one word; determining that the input is specified as a command in a plurality of the grammars, each of the grammars being associated with a respective instance of one application in a plurality of instances of the application each currently running on one of a plurality of devices; selecting one of the currently-running instances of the application to which to apply the command according a specified status of the selected instance of the application; and providing the command to the selected one of the applications.
8. A method implemented in a computer, comprising: registering each of a plurality of application grammars, wherein registering an application grammar includes determining whether a command in the application grammar conflicts with a command in another grammar registered in the computer; receiving input including at least one word; determining that the input is specified as a command in a plurality of the grammars, each of the grammars being associated with a respective instance of one application in a plurality of instances of the application each currently running on one of a plurality of devices; selecting one of the currently-running instances of the application to which to apply the command according a specified status of the selected instance of the application; and providing the command to the selected one of the applications. 11. The method of claim 8 , wherein the input is voice input.