Scheme is interesting because you can carry a Lisp around in your brain's pocket, implement it anywhere, and integrate it with anything. Accordingly there are Schemes (like guile and scsh) which work well with Unix, Schemes (like tinyscheme, s7, and guile again) which work well as embedded languages, Schemes (like Kawa) which work well with the JVM, etc.

Common Lisp can do the same, but it's a much bigger language so you see less of this effort and more standalone CL implementations like SBCL.