QtCreator is an IDE, I think the best one taht supports multiple platforms
Which Qt version you need, depends, where you want to deliver to.

If you want to build symbian apps, use Nokia Qt SDK or the Qt SDK Tech preview

I see, Nokia Qt SDK apparently contains QtCreator IDE plus other Nokia stuff like simulators…

What does this mean:
Development Host Desktop Qt Simulator Maemo5 Symbian
Microsoft Windows yes yes yes yes
Linux yes yes yes (via Remote Compiler)
Mac OS-X yes yes yes (via Remote Compiler)

Is symbian simulator/building possible in Linux/OS X? I got impression that remote compiler just builds you an installable package?

EDIT: Also it says in http://wiki.forum.nokia.com/index.php/Nokia_Qt_SDK_Remote_Compiler:
“As of the 1st of August 2010, the Remote Compiler is not supported under Mac OS X. “
Seems that Ubuntu is for me?

I have not used Mac OS X but i used windows, ubuntu and now fedora and i can tell you will be fine with either one just use the one your most comfortable with; Qt is cross platform and you can easily change platform if you need/want

Yes, I’m thinking that maybe remote compile is again supported in OS X in Qt SDK 1.1 Tech preview. So I’ll try either that or ubuntu version. Thanks for help!