Plasma/Live Images
Try and install Plasma from a live medium provided by several Linux distributions.
Shipping the latest code from Git
KDE neon
KDE neon builds Frameworks, Plasma and Applications on a continuous integration system.
You can use the Testing Edition for builds from Plasma/5.x branches or Unstable Edition for builds from master branches.
openSUSE
Krypton is an installable live image based on openSUSE Tumbleweed with the latest KDE software from Git master (unreleased) on top.
See also https://en.opensuse.org/SDB:Argon_and_Krypton
Ships Plasma 5.18 LTS
KDE neon
KDE neon builds Frameworks, Plasma and Applications on a continuous integration system.
The User Edition has Plasma 5.18
Kubuntu 20.04 Focal Fossa (development builds)
The Kubuntu development release daily iso builds now have Plasma 5.18 LTS.
http://cdimage.ubuntu.com/kubuntu/daily-live/current/
OpenMandriva Cooker and Rolling
OpenMandriva is a desktop centric, completely Plasma focused, distribution. The current rolling release branches include Qt 5.14.1, KDE Frameworks 5.67, and Plasma 5.18.0 and KApps 19.12.2.
openSUSE Tumbleweed
In addition to Git based versions there is openSUSE's rolling distribution "Tumbleweed" which ships the latest Plasma release tested with openQA:
Both 32 bit and 64 bit versions are available.
Ships Plasma 5.17
OpenMandriva Lx 4.1
OpenMandriva is a desktop centric, completely Plasma focused, distribution. Release 4.1 includes Qt 5.14.1, KDE Frameworks 5.66, and Plasma 5.17.5.
openSUSE Argon
Argon is an installable live image of openSUSE Leap with the latest Plasma release. See also https://en.opensuse.org/SDB:Argon_and_Krypton
Slackware
Alien BOB (Eric Hameleers) provides an installable Live image for Plasma 5 based on the development tree "slackware64-current" and the liveslak scripts. Login account/password are both "live". Use su or sudo to become root (using the "live" password).
Ships Plasma 5.16
Kubuntu 19.10 Eoan Ermine
http://cdimage.ubuntu.com/kubuntu/releases/eoan/release/
Manjaro
Manjaro KDE Edition is rolling release distribution. It provides the latest stable Plasma, KDE Applications, KDE Frameworks and Qt releases.
https://manjaro.org/get-manjaro/
KaOS
KaOS is a sophisticated Distro, which focuses completely on KDE. A modern packaging approach leads to stability and freshness at the same time. Small and helpfully community.
OpenMandriva Lx 4.0
OpenMandriva is a desktop centric, completely Plasma focused, distribution. Release 4.0 includes Qt 5.12.3, KDE Frameworks 5.58, and Plasma 5.15.4.
Ships Plasma 5.15
Kubuntu
Kubuntu 19.04 Disco Dingo, released in April, includes Plasma 5.15.4. The live ISO is available for download.
Ships Plasma 5.14
Debian
Official Debian 10 “buster” live images can be downloaded from debian.org/CD/live. There’re several desktop environment flavors, including KDE.
Ships Plasma 5.13
GeckoLinux
GeckoLinux is built directly from openSUSE packages and uses openSUSE repositories.
GeckoLinux NEXT Plasma includes the Plasma 5.13 desktop environment on top of the Leap 15.0 base system. It also includes KDE Applications 18.04 and the KDE Framework at version 5.47.0.
http://geckolinux.github.io/#download-next
GeckoLinux ROLLING Plasma can also be updated to Plasma 5.13.
http://geckolinux.github.io/#download-rolling
Ships Plasma 5.12 LTS
openSUSE Leap
The latest released Plasma LTS version is available as a live image with openSUSE's stable branch "Leap":
GeckoLinux
GeckoLinux is built directly from openSUSE packages and uses openSUSE repositories.
GeckoLinux STATIC Plasma includes the Plasma 5.12 LTS desktop environment on top of a Leap 15.0 base.
http://geckolinux.github.io/#download-static
Kubuntu
Kubuntu 18.04 Bionic Beaver, released in April, includes Plasma 5.12 LTS. The live ISO is available for download.