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' and is a operating system in the os & utilities category. There are more than 100 alternatives to Ubuntu Server for a variety of platforms, including Linux, Self-Hosted, BSD, Windows and Mac apps. The best Ubuntu Server alternative is Debian, which is both free and Open Source. Other great apps like Ubuntu Server are Fedora, Tails, Zorin OS and Manjaro Linux.
GNU-Darwin aims to be the most free software distribution. Our mission is two-fold: Focus on projects that leverage our unique combination of Darwin and GNU, and help users to enjoy the benefits of software freedom.
AcademiX GNU/Linux is a Debian-based Linux distribution developed specifically for education. The distribution was built on the Debian Linux (Stretch / Buster) distribution and contains free software for education.
dahliaOS is a modern, secure, lightweight and responsive operating system, combining the best of GNU/Linux and Fuchsia OS.
Darwin is the Open Source operating system from Apple that forms the basis for Mac OS X, and PureDarwin is a community project to make Darwin more usable (some people think of it as the informal successor to OpenDarwin.
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A new OS/2-based operating system from Arca Noae, codenamed Blue Lion, arrived today, May 15, 2017, after nearly two years in development.
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Elive provides a dynamic and clean interface without saturating the look. Nothing in the desktop is static. Simplicity and intuitive is one of its best points.
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ZevenOS is an Ubuntu -based GNU/Linux distribution with focus on providing a fast and easy-to-use system with BeOS-like user interface and support for older hardware.
AmigaOS is the proprietary native operating system of the Amiga and AmigaOne personal computers, introduced with the launch of the first Amiga, the Amiga 1000, in 1985.
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Visopsys (VISual OPerating SYStem) is an alternative operating system for PC-compatible computers, written “from scratch”, and developed primarily by a single hobbyist programmer since 1997.
