Support Phases Explained: LTS, Extended Support and End of Life
What the common support terms mean, how they differ between vendors, and what each one means for your patching.
General availability and active support
A release starts at general availability (GA). During its active or mainstream phase the vendor ships fixes, and often features and improvements, for that version.
Microsoft, for example, separates mainstream support from extended support for products such as Windows Server. The Windows Server page shows both dates for each version.
Security-only and extended support
After the active phase, many vendors move a version to a phase that receives security fixes only, sometimes called extended support. New features stop and some bug fixes stop, but critical security patches continue until the end-of-life date.
Paid programmes such as Microsoft's Extended Security Updates are separate from standard extended support. They are optional contracts that apply after regular support ends, and they have their own end dates.
LTS and standard-term releases
Some projects publish long-term support (LTS) releases that are maintained for longer than the others. Microsoft's .NET is a clear example: even-numbered versions are LTS with three years of free support, and odd-numbered versions are standard term with two years. See the .NET page for the current dates.
If you want fewer upgrades, choose the LTS line where a vendor offers one. If you want newer features sooner, accept the shorter window and schedule more frequent upgrades.
Rolling maintenance windows
Not every project uses fixed dates per version. Elastic maintains each major release for the longer of 30 months from GA or 18 months after the next major release, and keeps only the two newest minor releases of the current major under maintenance. See the Elasticsearch page.
For policies like this one, the date a version stops being maintained can depend on when the next version ships, so the dates are worth rechecking.
End of life
End of life (EOL) means the vendor no longer provides fixes, including security fixes, unless you buy a separate extended programme. Running an EOL version is not an immediate failure, but every new vulnerability found afterwards stays unpatched.
The EOL lookup lists dates for each tracked version and links to the vendor source, and the migration planning checklist covers what to do next.
Dates and policies are set by each vendor and can change. Always confirm on the vendor's own page before you commit to a plan. Open the EOL lookup.