[5-0] What is CLOS (PCL) and where can I get it? How do you pronounce CLOS?

CLOS (Common Lisp Object System) is the object-oriented programming
standard for Common Lisp. It is the successor to Symbolics FLAVORS and
Xerox LOOPS (Lisp Object Oriented Programming System). The acronym
CLOS is pronouned either as "See-Loss" or "Closs" ("Claws"), depending
on taste. PCL (Portable Common Loops) is a portable CLOS
implementation, and is available by anonymous ftp from 
   parcftp.xerox.com:/pub/pcl/ [13.1.64.94]
Also in the same directory are sources for CLX R5 and an inspecter.

Most Common Lisp implementations now include their own CLOS
implementations. Common Lisp implementations with native CLOS include:
MCL, {A}KCL, Allegro CL (including Allegro CL\PC), Ibuki, Lucid,
Medley, Symbolics Genera, CLOE, and Harlequin LispWorks. CMU CL uses a
customized version of PCL as their CLOS. However, not all native CLOS
implementations have as detailed a meta-object protocol as PCL. For
example, MCL 2.0 users sometimes use the july-1d version of PCL
instead of the native CLOS for precisely this reason.

The book ``The Art of the Metaobject Protocol'' (see below) includes
the CLOS Metaobject Protocol specification as chapters 5 and 6.  The
sources for the MOP spec itself are available from 
   parcftp.xerox.com:/pub/pcl/mop/ [13.1.64.94]
as the file spec.tar.Z, but this is no substitute for buying the
book, since the book contains a lot of useful explanatory material
beyond the spec. The Closette files related to the book are also
available from parcftp as the file closette.lisp.

The CLOS code repository is available by anonymous ftp to
   nervous.cis.ohio-state.edu:/pub/lispusers/clos/ [128.146.61.200] 
If you've got code you'd like to add to the repository, send mail to
Arun Welch, commonloops-request@cis.ohio-state.edu.