1. A system comprising: a machine-readable medium storing a plurality of generative grammar models; a request module configured to receive a request to generate a message; a retrieval module configured to select and access a generative grammar model from the plurality of generative grammar models in response to the request module receiving the request, the generative grammar model defining a message structure, the message structure including a plurality of lexical slots, the generative grammar model specifying a corpus of source data and a grammatical constraint for each lexical slot in the plurality of lexical slots; a message generation module, comprising one or more processors of a machine, configured to generate the message using the generative grammar model; and a communication module configured to cause the message to be published to one or more users.