Software developers don't always follow Microsoft's support model for operating systems.

THE CASE OF WINDOWS XP
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Although Windows XP reached its end-of-support date in April 2014, there were still variations of the operating system (specifically Embedded, Embedded for Point of Service, Embedded Standard 2009, and Embedded POSReady 2009) that continued to receive updates for many more years afterwards, with some going up until early 2019. Many updates could even be applied to consumer versions of Windows XP using a registry tweak.

Because Windows XP was still an extremely popular operating system at the time[1], many programs continued to support it for a couple more years. However, this started drying up during the mid-to-late 2010s as it declined in popularity and people moved to newer computers and operating systems. Apple's iTunes dropped support in September 2015. Google Chrome dropped support in March 2016. Mozilla Firefox dropped support in June 2018. Steam dropped support in January 2019. The list goes on.

THE CASE OF WINDOWS 7
=====================
Though Windows 7 reached its end of support in January 2020, Microsoft offered an official way for businesses to continue receiving updates on their existing systems for the next three years through the Extended Security Updates program, though support for that ended in January 2023. However, like XP, 7 also had some variations of the operating system (specifically Windows Thin PC, Windows Embedded Standard 7, and Windows Embedded POSReady 7) that could get updates for many years afterwards using the ESU program, with some going up to October 2024. Unlike XP, however, your system had to be eligible and authorized to install these patches.

Many programs continued to support 7 for many years beyond its end of life date, though support is now starting to dry up. OBS Studio dropped support in September 2022. Google Chrome dropped support in January 2023. Steam dropped support in January 2024. Discord dropped support in its desktop application in March 2024. LibreOffice still supports it with its previous stable release, but that loses support in November 2025[2]. Mozilla Firefox still supports it through ESR 115, but is scheduled to drop support in March 2026.


REFERENCES
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[1] https://gs.statcounter.com/windows-version-market-share/desktop/worldwide/2014
[2] https://www.libreoffice.org/download/download-libreoffice/?version=25.2.0&lang=en-US