A bit premature as we barely have something that compiles yet...

But then, why not...
I think you should start by reading
Qt's deployment documentation first. There are many good hints.
gerundt wrote:What directory structure should we use?
Since we this time only use WiX as setup system, I think we don't need the name "WiX" in directory. What think you about "/installer/windows/..."?
I doubt we'll have installer for other platforms than Windows so it could be just
win_installer or something like that. But whatever you choose, use low letter pathnames.
gerundt wrote:What name use we for the program list and start menue?
WinMerge 2.x use "WinMerge". Since people maybe install the new version parallel to the old version, we should use a other name. But which?
Really, we are far away from the state we want anybody than developers to even consider installing it. But my first thought is we want to replace old WinMerge 2.x version with new version. Why would users need/want two versions side by side? And installers are for users.
gerundt wrote:- WinMerge 3
- WinMerge 3.x
- WinMerge <CompleteVersion>
- WinMerge III
- WinMerge QT
- ...
WinMerge + version number sounds good too. Lots of programs use that scheme. But I also think WinMerge Qt (it is small 't'!) might be nice.
gerundt wrote:Which runtime files must we install?
Has somebody experience with installer for QT projects?
Yes, look at Cppcheck installer. Its been doing Qt installing for some time now. Basically its just normal MSVC runtime installation (using merge modules). And then selection of Qt DLLs, depending which modules are used. In our case probably (Qt core, Qt GUI and Qt XML).