ProcessWire: An Open Source CMS with a Powerful API

ProcessWire is a free, open-source content management system (CMS) and framework designed for ease of use, flexibility, and scalability. It features a customizable, hierarchical page structure, a powerful API for content management, strong multi-language support, and a secure, modular architecture that allows developers full control over content and design. Trusted for both small and large sites, ProcessWire offers a user-friendly editing experience and an expanding ecosystem of modules and tools.

https://processwire.com/