For hard RT you need both the OS and the language runtime to maintain certain constraints, and I am not aware of Lisp implementations satisfying that. Nothing t

For hard RT you need both the OS and the language runtime to maintain certain constraints, and I am not aware of Lisp implementations satisfying that. Nothing to be concerned about tho, it's a fairly small niche that is not addressed by most of the popular languages today too. (Doing soft-RT work in Common Lisp though)