Lisp and Scheme don't actually integrate with UNIX.
Their UNIX versions are handicapped versions of themselves.
Languages with rich runtimes and developer tooling are always shoehorned into POSIX model to "feel UNIX".
Their UNIX versions are handicapped versions of themselves.
Languages with rich runtimes and developer tooling are always shoehorned into POSIX model to "feel UNIX".
PLT Scheme (language) → Racket
DrScheme (environment) → DrRacket
They provide a rich graphical developer experience, with many features that are the genesis of modern IDEs, and nothing on their standard library and runtime depends on anything POSIX related.
The Lisps that "integrate well" with UNIX, like SBCL, do so by providing a UNIX text based repl without that graphical power, while using Emacs, an editor based on Lisp Machines, that even with SLIME is not quite like the commercial Lisps.
Same applies to any other language with a rich runtime, that makes the underlying OS irrelevant.
Instead, in a Lisp on Unix, I'll call mmap and either have to manually check for an error or use a wrapper which does that for me. If there is an error, I'll have to re-call mmap.
It's not terrible, and it's still a lot better than using e.g. C — but it's not as good as it could be in a Lisp-all-the-way-down system.