Topic summary
Ubuntu version history
Releases of Ubuntu—a Linux operating system mostly composed of free and open-source software—are made semiannually by Canonical Ltd using the year and month of the release as a version number. The first Ubuntu release, for example, was Ubuntu 4.10 and was released on 20 October 2004. Consequently, version numbers for future versions are provisional; if the release is delayed until a different month (or even year) than planned, the version number will change accordingly.
Releases are scheduled every April and October to incorporate new GNOME releases made every March and September. Free support is offered and includes security updates for "main" free software packaged. Every fourth release, scheduled for April of every even-numbered year, is designated as a long-term support (LTS) release, meaning it receives free support for five years. Non-LTS releases are designed as interim releases and receive free support for nine months. The Expanded Security Maintenance (ESM) service from the Ubuntu Pro subscription, which is free for personal use on up to five devices, extends long-term support to be ten-years long and include security updates for community-managed "universe" free software packages. The Legacy subscription add-on extends long-term support to fifteen years.
On 19 March 2013, the Ubuntu Technical Board reduced the support period for interim releases from eighteen months to nine. For LTS releases 10.04 and earlier, the desktop version received free support for three years, and the server version for five years. LTS release 12.04 harmonized the support period to five years and introduced the Extended Security Maintenance service as part of the Ubuntu Advantage subscription service. By 26 January 2023, Ubuntu Advantage was rebranded to Ubuntu Pro, and ESM to Expanded Security Maintenance as support for the Universe repository was added to the service. The paid Legacy Support was introduced on 25 March 2024, extending long-term support by two years, which increased to five years on 13 November 2025.