Mezzano

“The MIT Lisp machine system: Mezzano, a much more recent OS written in Common Lisp that runs on Arm rather than special hardware:”

“For Lisp I would recommend Edi Weitz's CL-PPCRE: Pretty much anything else from Edi Weitz is also great. Mezzano is quite elegant in my opinion, especially for an operating system. For example, this is the USB mass storage driver:…”

“mentioned in this thread: C * Lua * Redis (mentioned twice) * Ruby * SQLite C++ * Botan * ClickHouse…”

“Mezzano, an operating system written in Common Lisp (114 points)”