Latest release: 2.14.
Changes can be assigned to specific users
Open and Abandoned changes can be deleted
HTML emails and new templating framework
Support for receiving review comments by email
New Polymer based user interface
Support for elliptic curve/ed25519 SSH keys
Secondary index with Elastic Search (experimental)
Support for Git LFS
Access control for git submodule subscriptions
New change submission workflows: ‘Submit Whole Topic’ and ‘Submitted Together’.
Support for GPG Keys and signed pushes.
Release notes for releases prior to 2.12 can be found on the old documentation site.