Yes, it has the same spirit of S-expressions and shares the lovely square brackets with Rebol. The major difference is that Jevko is whitespace-agnostic: it has no notion of elements separated with whitespace.

Generally it's a simpler, more low-level thing. It could be used to build a Rebol-like language. You could add whitespace rules on that level.

A toy example: https://github.com/jevko/jevkalk

This one does not use whitespace as a separator, allowing spaces in identifiers at the expense of more brackets.