Lifecycle and Maintenance of Fedora
The Fedora Project maintains any given release X until one month after the release of X+2.
- Fedora 8 will be maintained until 1 month after the release of Fedora 10.
- Fedora 9 will be maintained until 1 month after the release of Fedora 11.
In practice, Fedora releases a new version about every 6 months, which means than each version of Fedora gets updates for about 13 months. This allows users to "skip a release" while still being able to always have a system that is under maintenance. If this is not suitable for you, you might want to take a look at Red Hat Enterprise Linux which is a commercial derivative of Fedora or one of it's free rebuilds.
You can find information on the project releases at Fedora Release Schedule .
Fedora Current Releases
Fedora Releases End of Life
Fedora Historical Schedules
Red Hat Enterprise Linux
Fedora is focused on free and open source software innovations and moves quickly. If you want a distribution that moves slower but has a longer lifecycle, Red Hat Enterprise Linux, which is derivative of Fedora or free rebuilds of that such as CentOS might be more suitable for you. Refer RHEL page for more details.