Are you Redhat lover or Redhat fan club? Nowadays Redhat move to commercial os, But
If you would like to use Linux like Redhat Enterprise Linux, try CentOS.
CentOS is an Enterprise-class Linux Distribution derived from sources freely provided to the public by a prominent North American Enterprise Linux vendor. CentOS conforms fully with the upstream vendors redistribution policy and aims to be 100% binary compatible. (CentOS mainly changes packages to remove upstream vendor branding and artwork.) CentOS is free. CentOS is now accepting donations via PayPal, please click the button for more information
CentOS 2 and 3 are a 100% compatible rebuild of the RHEL 2 and 3 versions, in full compliance with RedHat\'s redistribution requirements. CentOS is for people who need an enterprise class OS stability without the cost of certification and support.
I think CentOS 4 will release soon, because Redhat just released RHEL 4.0.
The Community ENTerprise Operating System