WordPress has its REST API which allow to retrieve all your data through JSON. You can use the data from your CMS into your pages without the WordPress PHP structure. Plugins are no longer required, just install the latest version of WordPress 4.7 or more and you’re ready to go.
For your development:
- Start off by adding the Postman Chrome Extension. You could also install the REST Easy Add-On if you use Firefox.
- www.hurl.it is a good website to parse the JSON results.
If you use Advanced Custom Fields you will need this plugin to exposes your AFC Endpoints in the WP REST API v2
ACF to REST API