All,
The CentOS-4 distribution (current version 4.9) will be at End of Life on February 29, 2012. That means there is only 3 months left in the life cycle.
This coincides with the date that the upstream provider stops releasing updates for their EL4 products.
Users who still need the EL4 platform can contact Red Hat for their Extended Lifecycle Support (ELS) product:
http://www.redhat.com/rhel/server/extended_lifecycle_support/
Be advised that the upstream provider does NOT release their ELS source code publicly and therefore after February 29, 2012 they will no longer release security updates for their EL4 product line.
Soon after 1 March 2012, the CentOS-4.9 tree will be moved off the main CentOS mirrors and placed on http://vault.centos.org/ where it will be available for reference.
All users currently using CentOS-4 are advised to begin planning the upgrade to CentOS-5 (EOL Date: March 31, 2014) or CentOS-6 (EOL Date: November 30, 2017) ... or a move to the upstream ELS program for EL4.
This will be the 3rd enterprise Linux distribution that the CentOS Project has taken to EOL, with CentOS-4.9 joining CentOS-3.9 and CentOS-2.1 in the vault.
If you have any questions, please use one of the getting help methods from the CentOS Wiki:
http://wiki.centos.org/Documentation?action=show
Thanks, Johnny Hughes