This note is just to confirm that the support period for Ubuntu 9.04 formally ended on Friday, October 23, 2010, and Ubuntu Security Notices no longer includes information or updated packages for Ubuntu 9.04.
The supported upgrade path from Ubuntu 9.04 is via Ubuntu 9.10. Instructions and caveats for the upgrade may be found at https://help.ubuntu.com/community/KarmicUpgrades.
Note that upgrades to version 10.04 LTS and beyond are only supported in multiple steps, via an upgrade first to 9.10, then to 10.04 LTS. Both Ubuntu 9.10 and Ubuntu 10.04 LTS continue to be actively supported with security updates and select high-impact bug fixes. All announcements of official security updates for Ubuntu releases are sent to the ubuntu-security-announce mailing list, information about which may be found at https://lists.ubuntu.com/mailman/listinfo/ubuntu-security-announce.
Since its launch in October 2004 Ubuntu has become one of the most highly regarded Linux distributions with millions of users in homes, schools, businesses and governments around the world. Ubuntu is Open Source software, costs nothing to download, and users are free to customise or alter their software in order to meet their needs.