If only... There were a number of browsers with "applets" in different languages later in the '90s, at least: Hotjava (however it was CapitalIzed) with Java,

If only... There were a number of browsers with "applets" in different languages later in the '90s, at least: Hotjava (however it was CapitalIzed) with Java, Grail with Python, MMM with Caml (light?), and something for Tcl (I think). You can find mention of them in the Emacs 21(?) browse-url code; well, maybe not the (why-you-should-not-use-) Tcl one. As far as I remember, nothing came of the proposed Guile version. There ought to have been one for NeWS, but I don't remember. Probably just as well Emacs/W3 didn't join in. There were also languages with "distributed scope", as opposed to "mobile code", particularly Obliq, and maybe Kali Scheme. I'm not sure why the concept seems to have died.