I don't know if any language can exist solely as repackaged knowledge. Sure, a language can very well start that way, but you now have n features that need to b

I don't know if any language can exist solely as repackaged knowledge. Sure, a language can very well start that way, but you now have n features that need to be integrated with each other in a still unknown way, which brings new challenges and new knowledge. And no language is static and no technique is completely generic, so any complex software will have issues that will need custom solutions that will again lead to the creation of new knowledge. For example Julia didn't invent multiple dispatch, but it's intention to use it to high performance numeric computing meant different constraints from Dylan or CL, which led to the creation of it's own unique paradigm around type specialization and promotion to make it work. But eventually people had troubles with extremely complex dispatch rules, so, thanks to the language also having repackaged the Lisp knowledge in itself, the language designers were able to create a unique macro to make dispatch rules turing complete (generated functions). And then people realized it could be used for source to source manipulation, for example in the state of the art ML project Zygote. You'll certainly find many examples like that in any minimally ambitious language.