A programmer, who wants to develop their own linear programming applications, can do so directly under Windows or under the Cygwin environment. For more information on Cygwin development see Cygwin devlopers.

In windows the programmer

• needs to include the C header file qsopt.h into the application's files to ensure successfull compilation,
• needs to supply the application's linker with a reference to the library interface file QSlib.lib, and
• needs to make sure that the application when executed is able to load the dynamic link library qsopt.dll.

Thus in Visual C++ a programmer needs to do the following:

• Add qsopt.h and QSlib.lib to the application's project. These files can be found in the folder {APP}/src, where APP is the folder the user chose during software installation.
• Add the folder that contains qsopt.h to the project's Additional Include Directories, which are defined in the project's General C++ Configuration Properties.

Since an application's executable dynamically links to qsopt.dll, that is it does not contain its own copy of the library code, it needs to load the library at runtime. Under the Windows Operating System applications search for dynamic link libraries in the following manner:

1. The directory in which the executable resides.
2. The current directory of the process that runs the executable. If the executable is started from a Desktop Icon, this is the same as the "Start In" directory shown in the Icon's Properties.
3. The System directory.
4. The WINDOWS directory.
5. The directories listed in the Path environment library.