There is an active and growing group of hackers trying to make CLOSOS a reality. The current progress can be viewed at https://github.com/robert-strandh/sicl (SICL is the Common Lisp implementation that will be used for CLOSOS)

I am one of the contributors, so please don't hesitate to ask questions or discuss ideas.

If you're starting from scratch, why not design a new Lisp? CL has never struck me as a particularly inspired language, and neither has the kind of code people write with it.

Or, if the idea is to leverage existing CL code, I'm sure with a little bit of effort SBCL could run as a unikernel and provide a good base for the system.

Awhile ago there was a standalone Lisp implementation called Movitz. What are your thoughts on that?

Hell no. Here is why:

1. The Common Lisp standard is brilliant. If your new Lisp is designed by anything less than a committee with people like Kent Pitman, Guy Steele, and Richard P. Gabriel, chances are that you will end up with something worse.

2. Common Lisp has one feature that people often forget about, but that is crucial for an operating system - you can rely on the fact that the semantics doesn't change. Lisp programs written in 1960 can usually be run on today's Common Lisp without modification, so there is hope that programs written today will still run properly even in centuries.

3. Common Lisp has the most powerful object system and the most powerful condition handling system. Both these features are invaluable for an operating system. This is actually my main motivation for contributing to this project. I want my programs to communicate via objects, and I want a system-wide mechanism for recovering from errors without crashing or unwinding the stack.

4. By relying on a very good existing language instead of reinventing this wheel, there is a chance that CLOSOS will actually get finished.

> I'm sure with a little bit of effort SBCL could run as a unikernel and provide a good base for the system.

Probably. But to make CLOSOS actually useful, we need an abstraction for having multiple first class global environments. And bolting that on top of SBCL without breaking existing things is about as painful as a full rewrite. The other big point is that SBCL values performance more than safety. But for CLOSOS, safety is crucial.

> Movitz

We intend to borrow some ideas from Movitz. But since we managed to bootstrap Common Lisp directly from Common Lisp, we hope that some things can be done more elegantly. The other project that should be mentioned here is Mezzano (https://github.com/froggey/Mezzano). We even borrow some code from Mezzano and are actively collaborating with its author.