Nathaniel (Mr Mime) Borenstein came up with something (atomicmail?) that was intended to be more functional than raw text but safer than free execution of unknown code.  I disremember the details.  I don’t think it ever got traction.

On Sun, Jul 30, 2023 at 7:59 PM Erik E. Fair <fair-tuhs@netbsd.org> wrote:

        Date: Mon, 31 Jul 2023 09:34:56 +1000
        From: George Michaelson <ggm@algebras.org>

        [...]

        Execute on read is just awful. But, now we have HTML to track "they
        read it" through URL fetch.

And then the utterly disastrous: JavaScript. It should be *eliminated*
from the WWW as the gross security violation it is.

        "don't run software from strangers",

        Erik Fair
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