BRiX: Advanced Computing Environment  
   Fast, no-kernel, single address space, data-centric, preemptive multithreaded, persistent, secure, multi-user operating system, with Crush function-based programming safe-language. Some code available. [Open Source, Artistic]
   http://brix-os.sourceforge.net/

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

Crush/BRiX: An Experimental Language/OS Pair  
   The usual variety of lively opinions, some of which are informed by study and quite insightful and useful in further understanding BRiX. [Slashdot]
   http://slashdot.org/article.pl?sid=02/08/18/2053259

BRiX: SourceForge  
   Fast, single privilege, single address space, preemptive multithreaded, persistent, data-centric, secure, multiuser OS, with safe language, reconfigurable graphical interface.
   http://sourceforge.net/projects/brix-os/

Choices Object-Oriented Operating System  
   Research OS coded in C++, architecture organized as frameworks of objects hierarchically classed by function, performance; customized by replacing subframeworks, objects; application interface is kernel objects exported via application/kernel protection l
   http://choices.cs.uiuc.edu/