The notion of a restricted server-side language for user scripts still sounds useful and an unfilled niche.
It seems modern microprocessors simply aren't designed to run untrusted code.
Is it though? I mean, has anybody stopped using Javascript as a result of Meltdown/Spectre?
True, Java applets largely died off, but that was as much because it took Sun WAY too long to ship the "Consumer JRE", coupled with a rash of Java security issues over a certain window of time, that made people scared to enable Java in their browsers. I doubt many more people disabled Java after Spectre/Meltdown, than before.
Well that was staggeringly prescient.