Common Lisp became an official ANSI Standard on December 8, 1994: ANSI X3.226:1994 American National Standard for Programming Language Common LISP (X3J13). Copies of the ANSI/X3.226 standard, which is nearly 1,100 pages long, may be purchased from the American National Standards Institute, 11 West 42nd Street, New York, NY 10036. For more information, visit the ANSI home page at http://www.ansi.org/.
A web version of the ANSI Common Lisp standard is not available. The official ANSI standard is available only in hardcopy form.
However, Kent Pitman of Harlequin, Inc. has written an HTML document that is derived (with permission from ANSI and X3) from the ANSI Common Lisp standard (X3.226) and related design documents. As Project Editor of X3J13 Kent Pitman managed the completion of the document which became the ANSI Common Lisp Standard.
The Common Lisp HyperSpec (TM) is not a definitive reference, but is much more practical for most casual browsing. It is available for online browsing from Harlequin or the CMU AI Repository.
Subject to some legal restrictions, you can download a copy for your own use and get much better performance. The gzipped tar file is just a little over 2MB, and unpacks into a set of about 2,300 files that is just a little over 15MB and contains approximately 105,000 links. The Common Lisp HyperSpec (TM) is Copyright © 1996 The Harlequin Group Limited. All rights reserved.