Linux Mint 3.0 Cassandra and Linux Mint 3.1 Celena will reach end of life on October 19th. Both releases were based on Ubuntu 7.04 which is planned to reach end-of-life at the same date.
Repositories will remain open for another while but no more updates or security fixes will be made available for these two releases.
Users of Linux Mint 3.x are asked to upgrade to Linux Mint 4.0 Daryna or to perform a fresh installation of Linux Mint 5 Elyssa.
Announcement from Ubuntu: “Ubuntu announced the release of 7.04 almost 18 months ago, on April 19, 2007. As with the earlier releases, Ubuntu committed to ongoing security and critical fixes for a period of 18 months. The support period is now nearing its end and Ubuntu 7.04 will reach end of life on Sunday, October 19th, 2008. At that time, Ubuntu Security Notices will no longer include information or updated packages for Ubuntu 7.04.”
Note: Linux Mint follows the Ubuntu release cycle with a new release every 6 months, a lifespan of about 1.5 years per release and 3 years per LTS release. LTS stands for Long Term Support. Linux Mint 5 is an LTS release.