Microsoft Alternatives

ReactOS
- ReactOS® is a free, modern operating system based on the design of Windows® XP/2003. Written completely from scratch, it aims to follow the Windows-NT® architecture designed by Microsoft from the hardware level right through to the application level. This is not a Linux based system, and shares none of the unix architecture.
Ubuntu
- Ubuntu is an operating system built by a worldwide team of expert developers. It contains all the applications you need: a web browser, office suite, media apps, instant messaging and much more.
  Ubuntu is an open-source alternative to Windows and Office.
FreeBSD
- FreeBSD® is an advanced operating system for modern server, desktop, and embedded computer platforms. FreeBSD's code base has undergone over thirty years of continuous development, improvement, and optimization. It is developed and maintained by a large team of individuals. FreeBSD provides advanced networking, impressive security features, and world class performance and is used by some of the world's busiest web sites and most pervasive embedded networking and storage devices.
Oracle Solaris 11
- Oracle Solaris 11 11/11 can be installed in a number of different ways - from a hands free server based automated installation to a text or graphical installation (Live Media). Installation is easy and fast, and can be customized with additional software using the Oracle Solaris 11 network based package management system.