17. A system for specifying voice commands for an application, comprising: a display that is configured to receive touch input; a processor and memory; an operating environment executing using the processor; a display showing content; and a voice command manager that is configured to perform actions comprising: receiving, at a global speech engine, an utterance comprising a command portion that specifies a command for the application to execute; identifying, from the command portion, an application-specific Voice Command Definition File (VCDF) for the, wherein the identified application-specific VCDF comprises definitions for voice commands associated with the application, listen for elements that each define a syntax on how to recognize a voice command, and a navigation element for launching the application in state corresponding with an identified voice command; identifying, using the application-specific VCDF, a voice command based on the command portion; and launching the application in a state defined by the identified application-specific VCDF based on the navigation element and the identified voice command.
17. A system for specifying voice commands for an application, comprising: a display that is configured to receive touch input; a processor and memory; an operating environment executing using the processor; a display showing content; and a voice command manager that is configured to perform actions comprising: receiving, at a global speech engine, an utterance comprising a command portion that specifies a command for the application to execute; identifying, from the command portion, an application-specific Voice Command Definition File (VCDF) for the, wherein the identified application-specific VCDF comprises definitions for voice commands associated with the application, listen for elements that each define a syntax on how to recognize a voice command, and a navigation element for launching the application in state corresponding with an identified voice command; identifying, using the application-specific VCDF, a voice command based on the command portion; and launching the application in a state defined by the identified application-specific VCDF based on the navigation element and the identified voice command. 19. The system of claim 17 , wherein the listen for elements for the command defines at least one of: a garbage parameter that instructs the speech engine to disregard content in the utterance based on the location of the content within the utterance and an optional parameter in the utterance that specifies that a command is recognized when the optional parameter is in the utterance and when the optional parameter is not in the utterance.