1. A system, comprising: a data store having a knowledge base stored therein comprising first knowledge represented in a structured, machine-readable format; and one or more computing devices configured to: generate second knowledge for inclusion in the knowledge base by inferring the second knowledge from the first knowledge; store the second knowledge in the knowledge base in association with related knowledge information identifying the first knowledge from which the second knowledge was inferred; respond to a first query using the second knowledge, the first query having been received subsequent to storage of the second knowledge in the knowledge base; dynamically generate third knowledge not represented in the knowledge base in response to a second query by inferring the third knowledge from the second knowledge; and respond to the second query using the third knowledge.