Should we sunset Windows 7 support?

[Jason A. Donenfeld]

Hey again,

About a year later, WireGuard on Windows keeps becoming more advanced
and integrated into the operating system, with better service
notifications, high speed multi-packet transmission, device arrival
notifications, software device management, and so on... the common
theme being that these are all made possible by Windows 8+ APIs. So
we're now carrying well over 1000 lines of Windows 7 compatibility
code, polyfills, and sometimes outright reimplementations. This is
nobody's idea of fun, and having lots of extra code (that receives
less and less testing) is usually a recipe for things to go wrong. The
added burden of Windows 7 slows progress on newer platforms.

So I really would like to sunset Windows 7 support at some point. The
party cannot go on forever.

However, according to [1], Windows 7 still makes up about 15% of
Windows installs. And I know for a fact that some pretty large
WireGuard deployments are running on Windows 7 boxes, sometimes
installed inside of ATMs... Whether or not that's a good idea, it is
happening. What to do?

My current thinking is to follow the Chromium project, or at least
watch attentively and see the fallout from their decision. After a 6
month extension due to the pandemic, Google is set to retire Windows 7
support in Chrome on January 15, 2022, which is exactly 100 days from
now. There are still some open questions, though: will Microsoft
follow by sunsetting Windows 7 support for Edge, or will they keep it
on life support even longer? Will Mozilla follow Chromium's decision
as well? Is tracking Chromium's decision sensible? It might be: web
standards tend to move awfully fast these days, and without an up to
date web browser, will Windows 7 users upgrade to Windows 11 [or
Linux]? It might not: the most important Windows 7 holdouts may well
be embedded machines that don't care about browsers anyway?

If anybody's thinking on this has evolved, I'd love to hear thoughts.

Thanks,
Jason

[1] https://gs.statcounter.com/windows-version-market-share/desktop/worldwide/