That's why I'm drastically limiting its initial functionality spec, GrandFather. I would like to see something that might work, first. Of course I'd like to be able to include modules, and read/write, and everything else, but the problem space explosion would make it completely un-doable. Just building an expression modeller that would handle a limited subset of Perl imperative and declarative code would be a non-trivial undertaking, and, of course, I expect that we will use modules in its execution. How much code is there in your Ook! interpreter??? This is a much bigger problem domain, even if we also throw out ReGex and things like that. My SPICE equation parser was 26 pages of code, no modules, and that was pretty trivial compared to this. Even if we just handle loops, conditionals, assignments and things like that, it's a big set of possible patterns.