Jaq is a clone of the JSON data processing tool jq, focusing on correctness, speed, and simplicity. It supports additional data formats like YAML, CBOR, TOML, and XML, and is designed to be a drop-in replacement for jq. Jaq also provides a library, jaq-core, for compiling and running jq programs inside Rust programs. The project aims to provide a more correct and predictable implementation of jq while preserving compatibility in most cases.