TXL

The TreeRewriting language TXL (developed by JamesCordy at Queen's University in Kingston, Canada) supports the definition of transformation rules on first-order terms of a given context-free grammar.

Rules not only specify a rewrite, but also the strategy for applying it. Strategies are chosen from a small set of implicit top-down search strategies augmented with explicit scoped application of parameterized subrules in the style of a first-order functional programming language.