There are 2 types of Ubuntu releases: Interim and LTS. Each Ubuntu LTS is maintained for 10 years total: 5 years of standard support + 5 years of ESM. Interim releases are maintained for 9 months.
For the Ubuntu release cycle please see: The Ubuntu lifecycle and release cadence.
We are happy to provide hosting for the following projects via the cdimage server. While they are not commercially supported by Canonical, they receive full support from their communities.
The cdimage server also hosts releases of other Ubuntu images not found on this server, such as builds for less popular architectures and other non-standard and unsupported images. For Ubuntu Desktop and Server on popular architectures, please see the links above instead.
Ports, Unsupported, and Experimental Images for Ubuntu
For old releases, see old-releases.ubuntu.com.