Dear WordPress users, version 4.4, named “Clifford”; is available.
What's new with WordPress 4.4
Appropriate image sizes on any device (ensuring a perfect fit). I wouldn’t consider this a big change, almost any premium theme out there takes care of that, but it’s even better now that this feature is by default.
This new feature is extremly useful, since WordPress now becomes an oEmbed provider as well; any oEmbed consumer is allowed to embed posts from their WordPress sites. Let’s understand how great is that: you simply add a post URL from another website into the editor and get an instant preview, complete with the title, excerpt, and featured image if you’ve set one. Users have been able so far to embed YouTube videos or tweets on their sites through this feature called oEmbed, but as of WordPress 4.4 they can embed WordPress posts as well!
REST API infrastructure
This change is huge, marking a new era in developing WordPress (to quote the guys at WordPress.org). It helps developers with a comfortable and clean way to build and extend RESTful APIs on top of WordPress.
You will notice the comment form fields order changed, the message textarea is now the first. Also, comment queries now have cache handling thus performance should be improved.
Terms now support metadata, just like posts.