Written in PHP, Amadeus is a Microframework or Content Management System used for building powerful websites.
It's a no-nonsense proprietary system, unique for its NO-DATABASE customizable taxonomy (content architecture)
It boasts a 20kb footprint, has a few modules and loads the html in a blazing < .05 seconds, using on average < 1MB.
It uses git technology to effectively manage content and code in a single online repository. Databases, though frowned upon, GCP may become the de facto Headless CMS for systems like Sunlight. A PWA was proven last November to bring a mobile app feel.
A jQuery version with no need for server technologies like php / .net / java is also in the works.
On a fresh machine, its best setup using command line with Magique (still ironing out a few chinks) and VSCode / PSPad.