Two kinds of XP...
I'm still stuck with XP on a box that dates from 2007 and which cannot be used with Win 7 or later (per Microsoft - the hardware doesn't support those OSs) - it's a long story, but I have absolutely no funds for either updated hardware or a more recent MS OS, and I have software I wrote that works well enough under XP but might not under anything else.
I am experimenting with running evaluation copies of Win 7, 8.1, and even 10 Preview under VMware's free Player on the box that supposedly cannot run any of those operating systems, and so far my tests show that only Win 7 seems to handle my apps without issues. Just my luck that Win 7 is now on the scrapheap too; maybe I can pick up a secondhand CD from a flea-market for a song, and run it under VMware until I can obtain the cash needed to move forward (maybe next year).
But I am mindful that there are at least two XPs out there: the version I have, totally unsupported by Microsoft (even their own VM app works only with Win 7 or later), and the version(s) that a bunch of well-heeled organizations have paid Microsoft to continue to update.
All I can hope is that someone breaks ranks and leaks their XP patches to the rest of us second class XPers (who are still pretty sizable in number despite a false claim that many of us had quit using the OS).