This paper discusses how the XLE general purpose ordered rewrite rule system is used to produce semantic representations from syntactic f-structures. The rules apply efficiently because they operate on the packed input of f-structures to produce packed semantic structures. In addition to rules which convert the syntactic structure to a semantic one, there are rules that use external resources to replace words with concepts and grammatical functions with roles. Although the system described here could by no means be described as a theory of semantics, from a practical stand point it can efficiently and robustly produce semantic structures from broad-coverage syntactic ones.