Contentful provides a web-based authoring interface that lets non-technical editors work with content after configuring a content model. Designers independently craft the interface for end-users, while the powerful APIs give developers a simpler way to load content into apps, websites, or even to build completely custom editing interfaces. Conntentful makes it easy to create and manage content in the cloud - and publish it everywhere: web, smartphones, tablets, signage, and whatever might come next.
GraphCMS enables developers to build powerful content APIs in a matter of minutes, while it gives content editors all the tools they need to manage their content. The hosted content APIs can then be easily consumed by websites, apps or any other platform or partner. The founders describe their product as content microservice, as it fits in any tool chain dealing with content.
Sanity is the platform for structured content. It comes with an open-source editing environment called Sanity Studio that you can customize with JavaScript and a real-time hosted data store.