This article is about applications that can be customized or extended through their own user interface. This is achieved by the interface’s ability to interpret users’ non-literal expressions, namely metaphorical and metonymic ones. Such increased interpretive intelligence depends on static and dynamic models of the domain and application, from which new figurative meanings are abducted automatically or semi-automatically. The system performs controlled modifications on the underlying models, based on its inferences about users’ intentions as they produce figurative utterances. Keywords End-User Programming, Metaphor, Metonymy, Abductive Reasoning, Interfaces for Knowledge-Based Systems.