Newlisp actually revives ancient mistakes in Lisp history. For example, there is no lexical scoping -- and "contexts" are not a substitute for lexical scoping. Lexical scoping ensures that bindings introduced within a scope cannot leak outside the text of that scope, avoiding subtle bugs that may manifest with dynamic scoping. Hence, Newlisp's lambda isn't really lambda, like Lisp 1.5's but very unlike Common Lisp or Scheme (absent side effects).
Newlisp's default (and most used) FFI is also... dangerous. You simply import a symbol from a shared lib and it gets bound to a procedure corresponding to a C call to that shared lib. No specifying of parameter types -- and most platforms do not encode parameter type information in shared libraries in a standard universal way. (Things like C++ name mangling, and COM, only apply to libraries written within their respective ecosystems.) But don't worry. Newlisp trusts you to get the parameter types right, because Newlisp is for the practical Lisp programmer. Woe betide you if you don't, though!
Guile's (system foreign) module provides a similarly dangerous FFI, but at least you can (and must) specify parameter and return types when you import a foreign procedure from a shared lib that way, allowing for checks for parameter correctness at the call site, if not the import site.
Newlisp's default (and most used) FFI is also... dangerous. You simply import a symbol from a shared lib and it gets bound to a procedure corresponding to a C call to that shared lib. No specifying of parameter types -- and most platforms do not encode parameter type information in shared libraries in a standard universal way. (Things like C++ name mangling, and COM, only apply to libraries written within their respective ecosystems.) But don't worry. Newlisp trusts you to get the parameter types right, because Newlisp is for the practical Lisp programmer. Woe betide you if you don't, though!
Guile's (system foreign) module provides a similarly dangerous FFI, but at least you can (and must) specify parameter and return types when you import a foreign procedure from a shared lib that way, allowing for checks for parameter correctness at the call site, if not the import site.