TOON (Token-Oriented Object Notation) is a human-readable serialization format designed to minimize LLM token usage while preserving lossless round-trip conversion with JSON. This monorepo provides the reference TypeScript implementation (`@toon-format/toon`) and a CLI tool (`@toon-format/cli`) for encoding/decoding TOON. The library features streaming encode/decode, tabular forms for uniform data, normalization of special JavaScript values (BigInt, Date, Set, Map), security hardening against prototype pollution, and a replacer function with path tracking. The CLI supports stdin/stdout conversion, auto-detection by file extension, token statistics, and delimiter options. The repository also includes an extensive benchmark suite comparing TOON against JSON, YAML, XML, and CSV across token efficiency and retrieval accuracy using multiple LLMs (Claude, Gemini, GPT, Grok). Results show TOON matches JSON's accuracy while using ~43% fewer tokens. A documentation site with an interactive playground is provided via VitePress. The codebase is well-structured with clean abstractions, streaming APIs, and thorough testing, though it relies on an external spec repository and has a single author, creating bus factor risk.
htmlparser2 is a fast, forgiving HTML/XML parser library for JavaScript. It provides a streaming, callback-based (SAX-like) interface that allows consuming documents with minimal allocations. The library includes a low-level tokenizer, a parser that handles HTML-specific semantics (implicit tag closing, foreign content like SVG/MathML, special tags like script/style), and adapters for Node.js and Web streams. It also offers DOM construction via domhandler and feed parsing (RSS, Atom, RDF). The architecture separates tokenization from parsing, enabling reuse of the tokenizer component. The codebase is well-structured, thoroughly tested, and uses modern TypeScript with strict settings.
sax-wasm is a high-performance SAX-style XML/HTML/JSX parser written in Rust and compiled to WebAssembly, with JavaScript/TypeScript bindings for Node.js and browsers. It provides streaming parsing of byte streams, emitting events for tags, attributes, text nodes, processing instructions, comments, CDATA, and doctype declarations. The parser is non-validating and focuses on raw speed, using SIMD instructions and optimized grapheme cluster handling. It includes a comprehensive TypeScript API with async generator support for streaming reads from ReadableStream. The repository contains the full Rust source, JS/TS bindings, build tooling (wasm-bindgen, wasm-opt), and extensive test suites covering XML, JSX, Angular templates, edge cases with multi-byte characters, and write-boundary splitting. While the parser is highly optimized and well-tested, the project appears to be in a stale maintenance state with no recent commits (last commit dated 2026-09-13, likely erroneous) and a small community following.