We've released UBUNTU16-64-STD, a new standard Emulab disk image with Ubuntu 16.04 LTS (Xenial Xerus) 64-bit. The image contains a 4.4.0 Linux kernel, gcc 5.4, systemd 229-4, etc. All Emulab services are launched and controlled via udev and/or systemd. You can find more information at https://wiki.ubuntu.com/XenialXerus/ReleaseNotes . Please test it out, and let us know at firstname.lastname@example.org if you find anything broken or generally useful packages that are missing.