RedHat

Founded in 1993, Red Hat is the premier Linux and open source provider. Rated as CIO Insight Magazine's Most Valued Vendor for the second consecutive year, Red Hat maintains the highest value and reliability rankings among its customers, and is the most recognized Linux brand in the world. We serve global enterprises through technology and services made possible by the open source model. Solutions include Red Hat Enterprise Linux operating platforms, sold through a subscription model, and a broad range of services: consulting, 24x7 support, Red Hat Network. Red Hat's global training program operates in more than 60 locations worldwide and features RHCE, the global standard Linux certification.

http://www.redhat.com