Others in this thread have mentioned some good ones: Smalltalk, Lisp Machines, and the JVM. Some others I would add: - Pilot was an OS that was essentially bar

Others in this thread have mentioned some good ones: Smalltalk, Lisp Machines, and the JVM. Some others I would add: - Pilot was an OS that was essentially bare metal Mesa. It was written in Mesa, only runs Mesa programs, and used Mesa language features for OS capabilities like safety: https://courses.cs.washington.edu/courses/cse550/20au/papers/CSE550.Pilot.pdf https://courses.cs.washington.edu/courses/cse550/20au/papers... - Cedar was both a PL and an OS: https://www.ics.uci.edu/~andre/ics228s2006/swinehartzellwegerbeachhagmann.pdf https://www.ics.uci.edu/~andre/ics228s2006/swinehartzellwege... - The Oberon OS and Oberon PL are highly coupled https://people.inf.ethz.ch/wirth/ProjectOberon1992.pdf https://people.inf.ethz.ch/wirth/ProjectOberon1992.pdf - Here's a Scheme OS called MrEd: https://www2.ccs.neu.edu/racket/pubs/icfp99-ffkf.pdf https://www2.ccs.neu.edu/racket/pubs/icfp99-ffkf.pdf