Ubuntu Server is described as 'The leading platform for scale-out computing, Ubuntu Server helps you make the most of your infrastructure. Whether you want to deploy an OpenStack cloud, a Hadoop cluster or a 50,000-node render farm, Ubuntu Server delivers the best value scale-out performance available'. There are more than 100 alternatives to Ubuntu Server for a variety of platforms, including Linux, Self-Hosted solutions, Windows, BSD and Mac. The best alternative is Debian, which is both free and Open Source. Other great apps like Ubuntu Server are Linux Mint (Free, Open Source), Manjaro Linux (Free, Open Source), Fedora (Free, Open Source) and elementary OS (Free, Open Source).
BunsenLabs Linux is a distribution offering a light-weight and easily customizable Openbox desktop. The current release is Helium, built on top of Debian (stable). The project is a community continuation of CrunchBang Linux.
Chromium OS is an open-source project, used primarily by developers, that aims to build an operating system that provides a fast, simple, and more secure computing experience for people who spend most of their time on the web.Chromium OS and...
MINIX is a POSIX-compliant Unix-like operating system based on a tiny microkernel running in kernel mode with the rest of the operating system running as a number of isolated, protected, processes in user mode.
antiX is a fast, lightweight and easy-to-install linux live CD distribution based on MEPIS and Debian's testing branch for Intel/AMD x86-compatible systems. antiX offers users the "Magic of MEPIS" in an environment suitable for old computers.