When Osterhout built Tcl, there was sort of nothing like it. I think you've identified one troubling point - Stallman sort of trashed Tcl as, I think, an effort

When Osterhout built Tcl, there was sort of nothing like it. I think you've identified one troubling point - Stallman sort of trashed Tcl as, I think, an effort to support Scheme. This was expressed in ESR's support of Python... Yeah, I know. But the resulting obscurity fed what I think is a high degree of quality in Tcl. Tcl's a bit big for embedding as "embedding" has evolved - in terms of PIC sized things. I use it mainly for desktop/laptop test rigs of embedded stuff but you're completely dependent on being able to serialize from the DUT. This being said, RasPi/Cubie/BeagleboneBlack sized ARM things will support a Tcl interpreter handily and I do that too.