WordPress version 4.4 was released on December 8, 2015. This release has been named Clifford, for Clifford Brown, keeping in tradition of naming releases after jazz musicians.
In this release, the database version is now 35700.
Twenty Sixteen Theme
New to this version is the Twenty Sixteen default theme. This theme is a classic design that is built to look great on any device.
WordPress ensures that your themes will work across any device by smartly resizing them as needed.
As of this version, WordPress has become an oEmbed provider. This allows oEmbed consumers to embed posts directly from WordPress sites. More oEmbed provider support has been added as well.
Under the Hood
REST API infrastructure
WordPress has integrated infrastructure for the REST API directly into the core. This means that developers can extend RESTful APIs on top of WordPress. This is the first part of a multi-stage rollout.
Metadata support for terms has now been added, just like posts.
Comment query improvements
To increase performance, cache handling ahs been added to comment queries.
Term, comment, and network objects
New objects were created to interact with terms, comments, anc networks.