I've been trying to read AMOP and looking at the Closette code. It seems to me that ABCL uses Closette for CLOS... but the original Xerox code seems to explicitly warn against using it for compiled CLOS. I was just wondering if this is perhaps the reason for the performance issues of CLOS in ABCL. Do other CL implementations use Closette? The text is "Load this source file directly, rather than trying to compile it." from here: http://homepage.stat.uiowa.edu/~luke/xls/xlispstat/other/closette/closette.l... Thanks!