Angstrom - Parser combinators built for speed and memory efficiency. tree-sitter - Parser generator tool and an incremental parsing library. (HN) DDL - Declarative data definition language for formally specifying binary data formats. Common Expression Language - Implements common semantics for expression evaluation, enabling different applications to more easily interoperate. (HN) pest - General purpose parser written in Rust with a focus on accessibility, correctness, and performance. (Web) unist - Specification for syntax trees. nearley - Streaming parser with support for catching errors gracefully and providing all parsings for ambiguous grammars. SwiftSoup - Pure Swift HTML Parser, with best of DOM, CSS, and jquery (Supports Linux, iOS, Mac, tvOS, watchOS). GoGLL - Generates a GLL parser and FSA-based lexer for any context-free grammar. The generated code is Go or Rust. Spicy - C++ parser generator that makes it easy to create robust parsers for network protocols, file formats, and more. Lark - Parsing toolkit for Python, built with a focus on ergonomics, performance and modularity. mpc - Lightweight and powerful Parser Combinator library for C. Awesome binary parsing - List of generic tools for parsing binary data structures, such as file formats, network protocols or bitstreams. North - Experimental SEVM (Scannerless Earley Virtual Machine) parser implementation. AST Explorer - Web tool to explore the ASTs generated by various parsers. (Code) Lezer - Incremental GLR parser intended for use in an editor or similar system, which needs to keep a representation of the program current during changes and in the face of syntax errors. (GitHub) (Code) GraphRedex - Open-source tool that empowers language designers to interactively explore their reduction graphs. Parsimmon - Small library for writing big parsers made up of lots of little parsers. awesome syntax-tree - Curated list of awesome syntax-tree, unist, hast, xast, mdast, nlcst resources.