pump.io : Social server with an ActivityStreams API. It's a stream server that does most of what people really want from a social network.
Grav : Grav is a modern open source flat-file CMS written in PHP
Data Science Toolkit : A collection of the best open data sets and open-source tools for data science, wrapped in an easy-to-use REST/JSON API with command line, Python and ...
GetSimple CMS : GetSimple is an XML based, stand-a-alone, fully independant and lite Content Management System.
apiato : apiato is a starter project, designed to help you build scalable API’s faster, by providing tools and functionalities that facilitates the development...
Simple Content Platform to manage any structured content.
A self-hosted headless and api-driven CMS.