This is Five Changes on Ubuntu 15.04
Ubuntu 15.04 is entering feature freeze, this mean, the final version of Vivid Vervet is ready to be released precisely on time.
This is five changes on Ubuntu 15.04 that attend highlight:
1) Ubuntu switch init manager from upstart to systemd
Ubuntu's developers decided that, even though they were a few days past the feature release freeze date, they would switch 15.04's default to systemd. The change will affect "Ubuntu desktop/server/cloud and the flavors like Kubuntu, but NOT ubuntu-touch." Ubuntu Touch, Canonical's Ubuntu for smartphones and tablets, is sticking with upstart because, "Migration to systemd is blocked on touch (too old kernels, some unported jobs), and was not scheduled for vivid."
2) Linux kernel upgrade to 3.19.3 version, not Linux kernel 4.0
3) Local menu is available as default menu scheme
4) Unity 7 is still shipped, not shining Unity 8
5) Updated applications, especially Firefox 37, and LibreOffice 4.4