The Adobe Experience Manager (AEM) is a premium content-management-system for complex enterprise-websites. AEM is part of the Adobe Marketing Cloud, that provides full service for digital marketing and digital communications.
Craft is a modern content management system with a focus on a “content first” strategy. It aims to make life enjoyable for developers and content managers alike, and has a smart developer concept of its own.
Kirby is a well established, professional flat-file CMS with a great continuity. Kirby was first published in 2009, but, due to the continuous development, it is as fresh and modern as its juvenile competitors.
Sitecake enables authors to edit static web-pages inline. These kind of CMS or website-editors are perfect, if you want to create a simple, static website that is subsequently editable.
Statamic is a premium Flat-File-CMS with a modern code base and an extensive set of functionalities. You can create simple blogs as well as websites of mid-range complexity. All without the need for a database.