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. Tree-sitter grammars can be reused in many different languages.
A tree-sitter based major mode for editing Git commit messages in GNU Emacs
Tree-sitter based major-mode for Swift in Emacs, with support for font-locking, imenu and indentation