Common Lisp, the Standard Language

Scope:

Provides Lisp vendor?s and other implementors with a common, large set of language elements for industrial-scale application portability.

Standards:

ANSI Common Lisp, aka X3J13, hosted by Lispworks, commonly referred to as "the Hyperspec" due to its incredible interconnectivity. The Franz Inc. version of the spec is here.

Reference Implementation

It seems that no implementation is truly "The Standard", but that's the intention.