[gaigepr]

Definitely not. It is still "in Diapers" as eduardoejp says in this thread. If you want to learn a lisp that has been around for a while, is proven, and is a fully featured language? Try SBCL (Steel Bank Common Lisp): http://sbcl.org/

Since SBCL is an ANSI compliant lisp, anything that should work for common lisp that isn't SBCL specific (This mostly applies to threading related functions/types if memory serves).

If this doesn't appeal to you after some research, check out one of the popular schemes.