I agree, although most CL and Scheme implementations seem to be stuck in the Lisp box, from which escape is painful. Racket (PLT Scheme), Chicken Scheme, and Lu

I agree, although most CL and Scheme implementations seem to be stuck in the Lisp box, from which escape is painful. Racket (PLT Scheme), Chicken Scheme, and Lush do a pretty good job of providing good access to the OS, but SBCL and CLisp (neither of which I've poked at in years, so there may be some magic library by now) always felt like they wished they were the OS and pretended there was no Unix, owing to the time when CL was standardized and this was sort of still true. Smalltalk implementations are pretty similar in this respect, although both language families are still pretty fun. Erlang and Inferno/Limbo are both sort of guilty of this, but for slightly different reasons. But it's pretty inconvenient around the borders, getting into and ot of the "real" OS. It's sort of a mixed blessing that nowadays, most developer OSs are (on some level) Unix: there's a baseline, a set of facilities that can be expected to be present and to behave a certain way, so most modern Lisp-like languages are pretty friendly to the OS (or at least provide an FFI to C). The downside is that the baseline is POSIX, a little stiff sometimes and often quirky for historical reasons. (Still waiting for Plan 9 to catch on...Maybe I should stop holding my breath.)