Already a handful of "how does this compare...?" postings but the standard for a systems-programming scheme is scsh, a find abstraction layer over POSIX dating from the nineties.
I took it to mean a scheme used for developing close to the hardware programs, where as maybe others are taking it to mean a language which can be used to write common scripts and tools used by Systems Engineers.
scsh is purely interpreted and interfaces well with user-level programs but was being put forth as a systems-programming tool - while this works for some definitions of systems programming, it doesn't for others, and it is this distinction that the parent was pointing out.