I am having a big 32 bit Visual C++ 6 based application. I am in the processing of porting it to 64 bit application running on 64 bit OS (64 bit machine). How easy/ difficult it can be if I completely do it with only Qt alone (not Visual C++)? I am considering Qt as there can be an option of running it as a Windows (32/ 64 bit) or Linux (32/ 64 bit) application. This application involves connectivity to database which is again going to be residing on 64 bit platform. Any issues developing 64 bit applications with Qt ? pls post your comments if there any related to this. thanks.