Open Source PHP Parser Generators

json-machine is an efficient and easy-to-use PHP JSON stream parser. It enables processing of large JSON files or streams without loading the entire content into memory, making it suitable for memory-constrained environments.​

Complete LALR(1) parser generator and engine (like BISON or YACC) but it's all done in PHP, and the input grammar is easier and more maintainable. Write your actions in PHP. Generate PHP output code. Drive your parser with PHP. Wanna make a language?

CommonMark is a PHP library that implements the CommonMark Markdown specification, allowing developers to convert Markdown into HTML. It provides a robust and extensible parser with support for additional syntax and extensions. The library is designed to be efficient and standards-compliant, making it ideal for applications that require consistent and reliable Markdown processing.

Many Tools: PHP-based context-free grammar (CFG) parser generator, simple scanner generator, and nascent object relational mapping/query language in PHP. Talks to Postgres, MySQL for now. Needs PHP5. Comes with (relies on) many convenience functions.