Programmers love to add the word “tree” to everything with concepts like binary trees, red-black trees, trie, tree-shaking, and now, Tree-sitter. While 'Tree-sitter' might sound whimsical, it represents a significant innovation in parsing, the fundamental task in understanding and processing code. Traditional parsing methods often face limitations in flexibility and efficiency, but Tree-sitter seeks to improve on this and more, while also doing this in real time with every key stroke. This is an ambitious goal and requires solving many difficult problems.