The very popular Linux distribution Ubuntu is upgraded to version 15.04.
Ubuntu 15.04 still runs on Linux kernel 3.19, instead of the recently released kernel 4.0. Systemd has replaced Upstart as the standard boot and service manager on all Ubuntu flavors except Touch.
For the developers there is Ubuntu Make (nee Developer Tools Centre) and continues to add support for new platforms, bringing the total to 15.
A lot of applications are upgraded to the latest levels, like Firefox version 36 & LibreOffice 4.4. Also this release offers several updates and improvements for LXC containers and this is the first version of Ubuntu to offer the LXD container management utility.
Ubuntu 15.04 will be supported for 9 months for Ubuntu Desktop, Ubuntu Server, Ubuntu Core, Kubuntu, Ubuntu Kylin along with all other flavours.
You can download Ubuntu 15.04 here.