taocpp/PEGTL

The Elegant Parser

A header-only C++ argument parser library. Supposed to be flexible and powerful, and attempts to be compatible with the functionality of the Python standard argparse library (though not necessarily the API).

scanf for modern C++

Rust parser combinator framework

A parser combinator library for Rust

Compile Time Regular Expression in C++

Python library for creating PEG parsers

RE2 is a fast, safe, thread-friendly alternative to backtracking regular expression engines like those used in PCRE, Perl, and Python. It is a C++ library.

A fast JSON parser/generator for C++ with both SAX/DOM style API