Quote Originally Posted by Morea
If I look in c:\qt\4.1.0\lib I find a lot of files, .a files. What is this?
Those .a files are called import libraries (.a extension is specific to MinGW, other compilers might different extensions, for example .lib). Import library is just a stub that eases the use of DLLs. You link with such library just like with normal static library, but in the runtime it loads the proper DLL and imports all symbols from it automatically.