There are many operating systems available to meet different needs. Some are more difficult to administer than others, but there should be a solution available for whatever you want to do.
While paying for a licensed product is always an option if you find the value in said product worth the cost, it is recommended to make sure that a "free" solution could not meet the same needs.
Proprietary / Licensed
- Microsoft Windows Server | Windows is not usually chosen due to licensing costs.
- Unraid | Linux-based, but requires the purchase of a license for usage past the trial period.
Entry Level / Easy
These are operating systems that are administered with a GUI/web-based frontend to focus on ease of use.
- YunoHost | Demo
- TrueNAS CORE | A FreeBSD-based NAS operating system with ZFS support. Published by iXsystems, TrueNAS and FreeNAS were "Unified" in late 2021.
- TrueNAS SCALE | A Debian Linux NAS operating system. Published by iXsystems, and based around work done for TrueNAS CORE.
- DietPi | Built for single-board computers like Raspberry Pi or Pine64 boards.
- Sandstorm | Demo
Intermediate / Headless
If you are comfortable managing your server using terminal, then these options will work for you. They do a lot of hard work for you and should be simple to administer when needed.
- Ubuntu Server | Debian-based server OS developed by Canonical Ltd.
- Rocky Linux | Fork/replacement for CentOS.
- Fedora Linux
- Debian | One of the two oldest Linux distributions that are still maintained. Stable, mature, and proven.
- Arch Linux | A light, simple distribution that provides a small foundation to build on. Rich documentation and a large community-maintained third party software repository make it a solid choice for Linux veterans. Tailored for experienced users.
- Gentoo Linux | A Linux distribution focused on building packages from source to best fit your system. Binary packages are available, but that's like, against the spirit duuude.
- Slackware Linux | The other of the two oldest Linux distributions that are still maintained today, it focuses on stability and sticking to its UNIX roots.
- FreeBSD | Almost as old as Linux itself, it is derived from BSD UNIX as developed at the University of California in Berkley. Used by Netflix as the OS powering its digital media delivery nodes.
- Alpine Linux | A tiny Linux distribution catering to power users who want to squeeze the most resources out of their systems.
Niche / Other
- Proxmox VE | An operating system focused on the management of a virtualization environment utilizing KVM as a hypervisor.
- XCP-ng | XenServer-based, offers a turnkey virtualization solution.