TriTan CMS
TriTan is a developer centric, headless, or nearly headless CMS.
...It also should not be seen as a replacement for WordPress, Drupal, Joomla or any of the top used CMS's out there.
The main purpose of TriTan is to give developer's an option that is geared toward how they think, how they code, and how they build websites. Although you can use TriTan for your traditional CMS needs, you can also use it to build API centric applications.
TriTan is pretty stable at the moment, but it is currently in beta and should no be used in production until release 1.0.