Technically speaking, Windows XP does not run at all on the PS3. The videos you may have seen were of people running Windows XP inside QEMU, an emulator, on Linux. Running XP in an emulator is very slow, and not at all usable for games.
Yes, it can run very well on Windows XP.
You can not install any form of windows on the PS3
You cannot run Mac on Windows XP. But you can run Windows on Mac
Tally 6.3 run on windows XP
Yes ofcourse, Windows Vista is upgraded version of Windows XP. Obviously it can run Windows XP applications.
They are "compatible" in the sense that many applications that run on Windows XP will run on Windows Vista.
Windows Vista can already run most XP applications, with no need for any additional software.
Yes. The Windows version of PCSX2 runs on Windows XP.
Yes indeed, any version of VB can run on Windows XP.
Yes World of Warcraft will run on all computers Windows 7, Windows xp, Windows Vista
No. Windows XP will not run on a computer with a 486 processor.
Yes. The Windows version of Safari runs on Windows XP.