See also:

• Computers: Software: Operating Systems: Open Source  (16)

• FunOS - Proposal for LISP oriented OS based on Assembly, Caml, FunScheme, a Scheme variant of LISP language.
• Novel OS Work - By Christopher Browne. Very brief, clear descriptions and some critiquing of many OSs, mostly research types, with many links. Puts much current activity in larger context.
• SPIN - Dynamically extensible, Exokernel-based, provides many core services: scheduler, kernel threads, domains, event dispatcher, security mechanisms, primitive VM operations. Blurs distinction between kernels and applications, which traditionally live in user-level address spaces, separated from kernel resources and services by an expensive protection boundary. Lets applications specialize the kernel by dynamically linking new code into running systems.