Dear Pro, I'm currently writing a book on OOP, and after exhausting the usual stuff, I'm now at advanced topics that only Common Lisp and other Lisp dialects tackle, including Method Combinations, Multiple Dispatch and Meta-Object Protocols. Are there good motivational examples that fit in a couple of pages? And/or are there good free software or source-available programs and libraries that are worth citing and sending my readers to, to illustrate the power and interest of those techniques? For good uses the standard CLOS method combination and multiple dispatch, I am quite familiar with ASDF; and for the multiple dispatch at least, I can cite the extended version of my ELS 2014 paper. What other code bases, papers or articles may I cite? —♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org “The reason truth is stranger than fiction is that fiction has to make sense.”