NixOS 17.09 “Hummingbird” has been released, the eigth stable release branch. See the release notes for details. You can get NixOS 17.09 ISOs and VirtualBox appliances from the download page. For information on how to upgrade from older release branches to 17.09, check out the manual section on upgrading.
NixOS 17.09 released
Published on Mon Oct 02 2017