Apertos  
   Object-oriented reflective OS, from Sony Computer Science Lab.
   http://www.csl.sony.co.jp/project/Apertos/

Object-Oriented Operating Systems  
   Short, annotated, alphabetically sorted list and links, part of larger system.
   http://www.cs.arizona.edu/people/bridges/os/oop.html

Iguana Project  
   Investigating use of object-orientation, computational reflection, and metaobject protocols (MOPs) to support dynamic customizing of (system) software.
   http://www.dsg.cs.tcd.ie/%7Ecoyote/

Athene  
   Next generation, commercial, kernel independent, all object and component based computing environment and OS that users can design to their specifications. Backend is built to run in almost any environment.
   http://www.rocklyte.com/athene/

SOS: SOMIW Object-Oriented Operating System  
   Most interesting research results: simple, generic, powerful object model; the concept of Fragmented Objects to structure distributed abstractions; developed flexible naming service, dynamic linking package, library of application oriented communication p
   http://www-sor.inria.fr/projects/sos/

Renaissance  
   Multiprocessor OO OS purely designed and implemented in object-oriented techniques, to give application programs transparent access to system and remote objects distributed in a network of machines. OO programming is an ideal approach for building distrib
   http://www.cs.purdue.edu/AnnualReports/95/AR95Book-120.html

ShagOS  
   Portable object-oriented microkernel OS, dynamically loaded device drivers, fully redesigned and rewritten many times in C++, runs on VAX, x86. Ongoing experiment in using O-O paradigm as framework for full OS, with distributed computing as main aspect in
   http://www.csh.rit.edu/~shaggy/shagos.html