The last Qt version that supported Windows xp?
I need to use Qt in windows xp,which version I should choose????
The latest available for that OS, which is the LTS release (5.6.2 at this time).
Qt 5.7 (mingw 5.3 build) works on WinXP SP3 (but mingw version lacks QtWebEngine module).
Also, I've tested Qt Creator 4.2.0 (built using Qt 5.7.0 / MS Visual C++ 2013) on XP SP3 - it works, but if you going to use MSVC, you should read more about XP support in MSVC versions.
Also Qt 5.7 (MSVC 2013 32-bit build) works on WInXP SP3 if you include
QMAKE_LFLAGS_WINDOWS = /SUBSYSTEM:WINDOWS,5.01
in your app's .pro file.