I just finished reading Sonya Keene&#x27;s <i>Object-Oriented Programming in Common Lisp</i> cover-to-cover.  There is a <i>lot</i> of stuff in there that just can&#x27;t be covered by a brief guide for sure, a lot of pretty useful stuff, knowledge of which would quite possibly cause one to structure one&#x27;s program in a substantially different way, if one knew about it.  I highly recommend reading it if you intend to use CLOS for anything serious, and poring over the extended case study implementing streams is useful too, tedious though it might be.  There are, however, some things that got changed between the printing of the book and the finalization of CLOS as we see in CL today.  We write a <i>describe-object</i> method instead of a <i>describe</i> method, for example, and there is no longer a <i>with-added-methods</i> special form.