39. A system for hosting a programming environment and processing user input comprising: an interaction environment executing in a virtual machine on a server; an information retrieval component provided by the interaction environment and in communication with a search index and a collection of information; and a user interface module provided by the interaction environment and in communication with the information retrieval component, the user interface module comprising: a transceiver receiving, during a first session between a user and an interaction environment, via one of a plurality of media gateways, a definition of an expression type, the definition specifying an expression format and a response type, and receiving, during a second session between a second user and the interaction environment, an expression having a semantic structure; a semantic evaluator identifying an expression format of the received expression as the expression format specified by the definition of the expression type, responsive to an evaluation of the semantic structure of the received expression; and a response generating component providing a response to the expression based on the identified expression format and responsive to an execution of a computer program associated with the response type specified by the definition of the expression type.
68. The system of claim 39 , wherein response generating component further comprises a means for generating a response to the expression, based on the response type specified by the definition.