Plasma/Live Images
Try and install Plasma from a live medium provided by several Linux distributions.
Shipping the latest code from Git
KDE neon Unstable
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 the Unstable Edition for builds from master branches.
OpenMandriva Cooker and Rolling
OpenMandriva is a desktop centric, completely Plasma focused, distribution. The current development branch ("Cooker") includes Qt 5.15.1, KDE Frameworks 5.75, Plasma 5.20.2 and KApps 20.08.2. The current rolling release branch includes Qt 5.15.1, KDE Frameworks 5.75, and Plasma 5.20.2 and KApps 20.08.2. OpenMandriva Lx is available for x86_64 (with a specially optimized version for Ryzen/Threadripper CPUs) and aarch64. RISC-V, armv7hnl and PPC versions are in development.
openSUSE Krypton
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 5.26 Beta
Fedora Rawhide
Fedora Development Release ships with the latest Plasma, including Beta releases. https://dl.fedoraproject.org/pub/fedora/linux/development/rawhide/Spins/
Fedora stable releases via COPR
You can install the latest packaged Plasma backported from Rawhide via the KDE SIG's COPR: https://copr.fedorainfracloud.org/coprs/g/kdesig/kde/
KDE neon
KDE neon builds Frameworks, Plasma and Applications on a continuous integration system.
The Testing Edition has Plasma 5.26 Betea
Ships Plasma 5.26
KaOS
KaOS is a sophisticated and independent distribution which focuses completely on KDE. A modern packaging approach leads to stability and freshness at the same time. Small and helpfully community.
Ships Plasma 5.25
KDE neon
KDE neon builds Frameworks, Plasma and Applications on a continuous integration system.
The User Edition has Plasma 5.25
Kubuntu 22.10
Kubuntu 22.10, released in October 2022, includes Plasma 5.24. The Live ISO is available for download.
http://cdimage.ubuntu.com/kubuntu/releases/22.10/release
openSUSE Tumbleweed
openSUSE's rolling distribution "Tumbleweed" ships the latest Plasma release tested with openQA.
Both 32 bit and 64 bit versions are available.
openSUSE Leap 15.4 (Argon)
An installable live .iso with the latest Plasma release on Leap 15.4 is available as Argon.
It's possible to install Plasma 5.25 on Leap 15.3 and 15.4 system using the provided repositories on the openSUSE wiki page.
See also https://en.opensuse.org/SDB:Argon_and_Krypton.
Slackware
Alien BOB (Eric Hameleers) provides an installable Live image for Plasma 5 which is re-generated at each update of the development tree "slackware64-current" using the liveslak scripts. Two login accounts/passwords are "live/live" and "root/root". Use su or sudo to become root (using the "live" password).
Ships Plasma 5.24
Kubuntu 22.04 LTS
Kubuntu 22.04 LTS "Jammy Jellyfish", released in April 2022, includes Plasma 5.24. The Live ISO is available for download.
http://cdimage.ubuntu.com/kubuntu/releases/22.04/release/
openSUSE Leap 15.4
The latest released Plasma LTS version is available on openSUSE's stable branch "Leap":
Ships Plasma 5.24 Beta
Arch Linux KDE Unstable Repository
While no live ISO is available, the 5.24 Beta can be tested on Arch Linux by adding the KDE Unstable Repository.
Gentoo
While no live ISO is available, 5.24 Beta is available (masked) in the official Gentoo ebuild repository, as usual, to build it from source. ~arch users simply unmask it via this /etc/portage/package.unmask file, while arch users will additionally need kde-plasma-5.24.accept_keywords and kde-frameworks-5.90.accept_keywords files.
Gentoo users may easily test changes posted by developers for testing before committing via user patches mechanism.
FreeBSD
While the packages are not built on the build cluster, you can fork the port tree from
https://github.com/freebsd/freebsd-ports-kde/tree/plasma5-5.24
and build them yourself.