The Zend Framework for PHP. You can find the code here, and the documentation here. It has since been renamed to Laminas.

Slug
zf

A major change in how I work with Laravel

I have been a PHP programmer for years, having used it without frameworks, to frameworks like Zend Framework (now rebranded as Laminas) and Laravel, to custom in-house frameworks. At the same time, I went from using it with JavaScript in its various versions, to using the jQuery library with jQuery UI and various add-ons like DataTables.