A few moments ago, KDE announced the general availability of the RC (Release Candidate) build of the soon-to-be-released KDE Applications 16.04 software suite for the KDE Plasma 5 desktop environment.

KDE Applications 16.04 Release Candidate (16.03.90) has been tagged and released today, April 7, 2016, which means that it arrives one day late from its initial schedule on April 6. As usual, the KDE developers have managed to fix as many issues as possible since the Beta build announced on March 23.
Now that KDE Applications 15.12 has reached end of life with the last maintenance build, version 15.12.3, the time has come for the KDE team to move on to the next major version, KDE Applications 16.04. This should see the light of day in approximately two weeks from the moment of writing this article, on April 20, 2016.
"With the various applications being based on KDE Frameworks 5, the KDE Applications 16.04 the quality and user experience," reads today's announcement. "Actual users are critical to maintaining high KDE quality, because developers simply cannot test every possible configuration. We're counting on you to help find bugs early so they can be squashed before the final release."
After its April 20 unveiling, KDE Applications 16.04 will receive three maintenance builds, KDE Applications 16.04.1 on May 10, KDE Applications 16.04.2 on June 15, and KDE Applications 16.04.3 on July 12. But until then, you can now download and test the Release Candidate version. Don't forget to report bugs, if you find them.