How To Install And Test KDE Plasma 5 On Ubuntu 14.04

KDE Plasma 5 is hitting release candidate now: Schedules/Plasma 5 - KDE TechBase.

How can I install plasma 5 in Ubuntu 14.04.

Trusty

Since Dec, 05 2014, project neon is no more available as a PPA, unfortunately.

Utopic

Utopic is shipped with Plasma 4. If you want Plasma 5 there is a KDE Next PPA (which will provide updated KDE too), but it'll replace the current installed KDE

Install

sudo apt-add-repository ppa:kubuntu-ppa/next
sudo apt update
sudo apt install kubuntu-plasma5-desktop
sudo apt full-upgrade

And finally, after save all your work:

sudo reboot

Sources

Kubuntu CI: the replacement for Project Neon - blogs.kde.org
Frameworks/Binary Packages - KDE Community Wiki

I am writing answer because may some one be looking for answer in 2015 and all the answers above are outdated and won't work on ubuntu 14.04.2 trusty tahr(I have tried all). Friends. I was wondering to install kde on my ubuntu 14.04 and followed almost all online tutorials but in vain. To be frank, I run all desktop environments on my ubuntu( which are GNOME, Cinnamon, Unity, LXDE, XFCE, Compiz etc.) but I only failed in installing kde plasma desktop. So I came upon a solution and now have installed that succesfully(Hurrah!!). Just open the terminal and type below commands:

sudo add-apt-repository ppa:kubuntu-ppa/backports
sudo apt-get update && sudo apt-get dist-upgrade
sudo apt-get install kubuntu-desktop

And then Logout and Re login and select kde desktop. You are set. This one is updated ppa and works on ubntu 14.04 trusty. I have tried myself and it worked. You can also have a look at the ppa page at Launchpad ppa link.