This is a resource site of free GUI programming: To obtain the maximum execution speed, wxWidgets cross platform GUI library in C++ is strongly recommended; To build a prototype or verify something swiftly, Rapid-Q is a good candidate in BASIC; In Windows system, Reginald, a free REXX intepreter comes with a GUI library, also could be a rapid programming tool. For FreeBASIC, it remains the simplicity of BASIC language, and adds an interface to call external C libraries (DLL), including wx-c, a C wrap of wxWidgets.