There are many possible reasons why Tangential EOS could fail to install.

While you are booted into the live installation system, installer activity is logged to ~/endeavour-install.log. Reviewing the log may help you determine what happened.

If the installer completed, the log is copied to ~/taneos-install.log. You can review it after booting into the new system and troubleshoot anything that didn't work correctly.

If you want to use Tangential EOS as a multi-boot system (for example, to run Windows and Linux on the same machine), you can . . . but it's not tested and that's not really what it's intended for. Scott is only using Tangential EOS in virtual machines or as a machine's sole operating system.

If you decide to do it anyway, refer to the base system's guidance. You'll at least need to change the bootloader settings, since Tangential EOS has the boot menu disabled (set to a zero-second timeout) by default. Aside from that, it should work . . . probably.

Tangential EOS is based on EndeavourOS, which is itself based on Arch Linux. Its primary software management system is pacman, which has been preconfigured with the official EndeavourOS and Arch repositories. The system also includes the yay package manager for building and installing packages from the Arch User Repository (AUR), and the Flatpak package manager preconfigured with the Flathub repository.

From the command line, you can manage native packages with pacman or yay, AUR packages with yay, and Flatpak packages with flatpak.

From the graphical interface, you can manage native, AUR, and Flatpak packages with Pamac by Manjaro, which is named Add/Remove Software in the main menu. The system will notify you if updates are available. You can also manage native and Flatpak packages (but not AUR packages) with Discover by KDE.

Tangential EOS is just EndeavourOS with some tweaks, which is itself just Arch Linux with some tweaks. Don't think of it as a "true" distribution, but as a customized installation of the one it was built on. You'll keep getting updates as long as the base distribution makes them available. If you want to "revert" to the base system, you can:

• Set the KDE Plasma theme to something other than Tangential Breeze.
• Set the Plymouth bootsplash theme to something other than Tangential.
• Uninstall the "taneos-custom" package.

This should leave the system in a working state with nothing but residual settings from Tangential EOS, which can be deleted if you come across them or if they cause any issues.

Yes! Tangential EOS adds three executable command-line scripts in /usr/bin:

• jfu – EXPERIMENTAL, use with care! – Just f***ing update software from all supported package systems
• tangential-apply-branding – Sets the system name and icon to Tangential EOS (runs as an automated process on startup)
• tangential-reset-user-defaults – Re-applies the default user customizations apps (may overwrite some of your preferences!)

That's not a question. And what's wrong with you? Are you some kind of sociopath? I do not understand why people want to go back to the dark ages (heh) of computing. But go ahead, set things up however you want.

The Tangential Breeze theme for Plasma is based on Breeze Twilight, which uses light mode for apps and dark mode for the taskbar and main menu. You can switch over to Breeze Dark for the dark, depressing, sociopathic experience if that's what you like.

Tangential EOS will override some apps that stubbornly default to dark mode no matter how the system is set up. These include Blender, GIMP, PyCharm, Shotcut, Visual Studio Code, and others. When possible, I configured them to follow the user's preferences. When that option wasn't available, I set it to use light mode . . . but you can always change it in the app's settings.