Welsh rarebit - Wikipedia — This is a really well-written article.
Tree-sitter｜Introduction — «Tree-sitter is a parser generator tool and an incremental parsing library. It can build a concrete syntax tree for a source file and efficiently update the syntax tree as the source file is edited.»
vim/README_VIM9.md at master · vim/vim — «This is an experimental side of Vim. It explores ways of making Vim script faster and better.»