# What is ApostropheCMS?
- a headless API built-in
- a field schema API to create any kind of content types you need
- extensibility through a module ecosystem
- a great UI for creating content, including in-context editing
- robust localization to support any number of language or locale content variations
For developers, it offers a site building API that gives you the power to fully customize the website experience without needing to be a Node.js expert. For content editors, the true WYSIWYG experience supports improved editorial flow.
In short, it recognizes pain points on both sides of the CMS experience and relieves them.
# Give it a test run
Please try the Apostrophe demo for yourself if you haven't yet. That hands-on experience will provide valuable context as you learn about building with Apostrophe. Take notice of key features, including:
- in-context editing
- switching between "Published" and "Draft" modes
- content creation through the admin menu