When compiling a C++ application with a C++ library like ILOG CPLEX in ILOG Concert Technology, you need to tell your compiler where to find the ILOG CPLEX and Concert include files (that is, the header files), and you also need to tell the linker where to find the ILOG CPLEX and Concert libraries. The sample projects and makefiles illustrate how to carry out these crucial steps for the examples in the standard distribution. They use relative path names to indicate to the compiler where the header files are, and to the linker where the libraries are.