From The Free On-line Dictionary of Computing (30 December 2018) :
Tiny Clos A core part of Common Lisp Object System (CLOS) ported to Scheme+and+rebuilt+using+a+MOP+({Metaobject+Protocol">Scheme and rebuilt using a MOP ({Metaobject Protocol). This should be interesting to those who want to use MOPs without using a full Common Lisp or Dylan. The first release works with MIT Scheme 11.74. ftp://parcftp.xerox.com/pub/mops/)">(ftp://parcftp.xerox.com/pub/mops/). E-mail: Gregor Kiczales. Mailing list: mops (administered by ). (1992-12-14)