Since there's been talk about rewriting the ABCL compiler which is old, messy and not very optimizing, I wonder if Truffle can be a useful technology to base a new compiler on. Not as the default because it requires Java 9 (or perhaps 8), but at least as a future-proof solution. It seems to me that getting started is not hard - just map the Lisp S-expression based AST to a Truffle AST; optimizations can follow incrementally. What do you think? I don't have the resources to work on it anytime soon, I'm letting my own projects slip sadly - it would be great to work on it. Still, maybe someone else is interested. I can contribute some design and code reviews, if need be, but little actual coding.