Shuttleworth announced on 4 May 2015 that Ubuntu 15.10 would be called Wily Werewolf. He initially expressed hope that the release would include the Mir display server, but it was released on 22 October 2015 without Mir. It was the 23rd release of Ubuntu.
Ubuntu 15.10 eliminated the disappearing window edge scrollbars in favour of the upstream GNOME scrollbars, a move designed to save developer time in creating patches and updates.
In reviewing the release, Chris Jones wrote, "Ubuntu 15.10 as an operating system for Review is pretty lackluster. There's nothing new as such and there's nothing we can really say that is going to change your opinion from its predecessor, 15.04. Therefore, we recommend you to upgrade either out of habit and according to your regular upgrade schedule rather than out of a specific necessity for a specific feature of this release. Because there is really nothing that could possibly differentiate it from the older, yet still very stable 15.04 release. But if you're going to stick with 15.04 for a little longer, we do recommend that you look at upgrading the kernel to the latest 4.2 branch. It is worth it. If you really want a reason to upgrade? Linux kernel 4.2 would be our sole reason for taking Ubuntu 15.10 into consideration."
Joey Sneddon of OMG Ubuntu noted, "For a release named after a terrifying mythological creature Ubuntu 15.10 is surprisingly tame. There are no dramatic transformations, no bone popping or shirt ripping and certainly no hair sprouting under the milky eye of full moon. In fact, a new wallpaper and change in scrollbar appearance is about as shapeshift-y as this werewolf gets."
Steven J. Vaughan-Nichols of ZDNet praised the release for its integration of cloud services, such as the new Ubuntu OpenStack cloud deployment and management tool, OpenStack Autopilot as well as its server tools. Ubuntu's machine container hypervisor, LXD, included by default in 15.10, was singled out. Vaughan-Nichols concluded, "with these advances, chances are you're more likely to use Ubuntu, hidden behind the scenes, on clouds and servers."
A Hectic Geek review noted problems with X.Org Server crashes and concluded "If you use Ubuntu 14.04 LTS and if it's working out for you, then there really is no need to switch to a non-LTS release, especially to the 15.10."
A review on Dedoimedo identified problems with Samba, Bluetooth, desktop searching, battery life and the smartphone interface and found the release inconsistent, saying, "unpredictability is horrible. Give me a good experience, or give me a bad experience, but please try not to seesaw between them erratically. Continuous, steady change in behavior, any which way." The review concluded, "it underperforms compared to some of its siblings and ancestors. Not the best, definitely not worth a perma upgrade, but you might find it more palatable to your hardware and use cases. Overall, though Wily isn't the best of distros. It sure gave me the willies. 7/10."