Indeed The same person I mentioned in here suggested either Scheme or "if I dare" Common Lisp, also suggesting upon a further request of mine

• CLISP: "light and 'simple'",
• SBCL: "fast and powerful. But also complex",

as implementations, and

• CLiki the common lisp wiki: "to begin with", and the books
• Practical Common Lisp,
• Successful Lisp,

as learning resources; and The CHICKEN Scheme Compiler for Scheme.