I'd like you people to check the GYS scripting engine (written in C++; Lesser GPL licence): http://gys.sourceforge.net/ I developed it for personal purposes and want just to share this library now. It's the "pure" interpreter, developer can easily define his *own* language functionality and "semantics". The interpreter can work with: - expressions - binary, unary postfix and prefix operators - variables and constants - "commands" - conversions - values of different types Also there's a sample procedural language called 'stdGYS' developed using GYS engine. Its features are: - 8 basic types (void, bool, int, double, char, string, vector, function) with defined operators and conversions - about 60 standard built-in functions (IO, math, vector functions, conversions, threading, script execution etc.) - for, while, do loops - if-else if-else and return statement - dynamic half-nonuniform vectors - functions as first-class members (e.g. can be passed and returned by other functions) - multithreading - recursion The interpretation is runtime and developer doesn't have to deal with stack. The main feature is the possibility to make your language look and work just like you want (well… almost). I'd like to know your opinion. Thanks.