Try and install Plasma from a live medium provided by several Linux distributions.
Chakra is a GNU/Linux distribution with an emphasis on KDE and Qt that focuses on simplicity from a technical standpoint and free software. The downloadable ISO features a bootable environment that allows you to test the system before installing it.
The Fedora KDE Spin comes with Plasma. New minor Plasma versions are pushed as regular updates for Fedora installations but live media may contain a slightly older release (depending on Fedora’s release cycle).
- KaOS is a rolling, independent, built from scratch distribution, focused on Qt and KDE. It makes regular ISO releases available, so any (new) user is not confronted with a large or complicated first update.
KDE neon builds Frameworks and Plasma on a continuous integration system for its Developer Edition.
You can use the stable version for builds from Plasma/5.x branches or unstable version for builds from master branches. The user edition has builds from released software.
- openSUSE Tumbleweed ships the latest stable Plasma 5 release.
- openSUSE Leap ships Plasma 5 but without live images.
- Argon and Krypton are openSUSE live images shipping the latest KDE software from git (unreleased) for Leap and Tumbleweed, respectively.
- While Argon and Krypton ship unreleased software build from git, Krypton stable provides builds of the latest released version (Alpha, Beta)
- SUSE Studio Gallery contains various appliances with KDE Plasma desktop.
Alien BOB (Eric Hameleers) provides an installable Live image for Plasma 5 based on the development tree "slackware64-current". Login account/password are both "live". Use su or sudo to become root (using the "live" password).