Debian GNU/Linux is a free distribution of the GNU/Linux operating system. It is maintained and updated through the work of many users who volunteer their time and effort. - Read more

Since 1983, developing the free Unix style operating system GNU, so that computer users can have the freedom to share and improve the software they use. - Read more

Linux - For the community, by the community, Linux strives to be the central source for informed, reasonable, and intelligent Linux information, software, documentation and answers across the server, desktop/netbook, mobile, and embedded areas. - Read more

Red Hat is the world's leading open source technology solutions provider with offerings including Red Hat Enterprise Linux, open source applications, security and systems management, virtualization, Services Oriented Architecture (SOA) solutions, server and desktop operating systems, Java application software and services, and the JBoss Enterprise Middleware Suite. - Read more