opening exe files, comercial version vs opensource

[Gily]

Hi All
I go on with my program and done so far cool image proccesing, thanks!
few more questions:
1.I sent my exe file to my freind but he can't open it. does one need something installed to see the application? do I need to send more files?

2.does the commercial version of QT better then the opensource ? what are the differences?
3.the email support group http://lists.trolltech.com do they answer? didn't get any answer from them when I post to the list, I thought it is QT support
thanks