As announced on emacs-devel mailing list:

http://lists.gnu.org/archive/html/emacs-devel/2016-09/msg00451.html

“Highlights of this release include:

• Emacs can now load shared/dynamic libraries (modules)
• Experimental support for Cairo drawing
• Enhanced network security (TLS/SSL certificate validity and the
  like)
• New minor mode ‘electric-quote-mode’ for using curved quotes as you
  type
• Character folding support in isearch.el
• Xwidgets: a new feature for embedding native widgets inside Emacs
  buffers
• New and improved facilities for inserting Unicode characters”