Makes one wonder if an OS should be built using LISP these days to make available that kind of hackability. Or port Genera OS [1] to x86 or arm. The languages used by the VPRI project were bootstrapped on lisp if I recall correctly [2]. It would be great if that projects code was released as open source too.
[1] http://wiki.c2.com/?GeneraOs [2] http://www.vpri.org/writings.php