If you want a language that doesn't change it's hard to beat C which has only added extremely minor non-compatibility-breaking features every 15 years or so.

Not sure what the author is on about about it being difficult or not practical when most all of Linux userland is written in it.

The link is an HTTP proxy to the original content at gemini://zaibatsu.circumlunar.space/~solderpunk/gemlog/lua-as-a-practical-soft-bedrock-language.gmi