Kubuntu team has just announced the new release of Kubuntu 15.04 Vivid Vervet. This new stable version of Kubuntu 15.04 brings many improved applications, redesigned KDE Plasma 5 to work smoother for daily use. You will find many updated KDE standard applications on this release plus some other KDE compatible applications.
Quote from the release note:
Plasma 5, the next generation of KDE’s desktop has been rewritten to make it smoother to use while retaining the familiar setup. The second set of updates to Plasma 5 are now stable enough for everyday use and is the default in this version of Kubuntu. Kubuntu comes with KDE Applications 14.12 containing all your favourite apps from KDE. This is the 14.12.2 update with bug fixes and translation updates. Several applications have been ported to KDE Frameworks 5 but those which aren’t should fit in seamlessly. Non-KDE applications include LibreOffice 4.4 and Firefox 37
For Kubuntu lovers, you may download the Kubuntu 15.04 ISO and start install it on your computer or virtual machine. Make sure you have a good internet connection to download 1.2 GB ISO file.