JITty: A Rewriter with Strategy Annotations. We demonstrate JITty, a simple rewrite implementation with strategy annotations, along the lines of the Just-In-Time rewrite strategy, explained and justified in [4]. Our tool has the following distinguishing features: It provides the flexibility of user defined strategy annotations, which specify the order of normalizing arguments and applying rewrite rules. Strategy annotations are checked for correctness, and it is guaranteed that all produced results are normal forms w.r.t. the underlying TRS. The tool is “light-weight” with compact but fast code. A TRS is interpreted, rather than compiled, so the tool has a short start-up time and is portable to many platforms.