[grepLeigh]

I wrote some Jboss 5 code in 2009 (ish) that JUST hit the end of Red Hat's Extended Life Support in 2022. JBoss 5 EoL was announced in 2016, but you can purchase 5-6 years of critical security fixes with Red Hat's ELS.

That's only 15 years, but in some industries maintaining a stable software configuration is mission critical. If the software gets changed/upgraded, expensive certifications have to be re-done (e.g. FAA's certification for aircraft software).

But that's only when changing the code is DRAMATICALLY more expensive than freezing. In most cases, you want your codebase to be evolving to meet the changing requirements of whoever needs the software.