All client programs must include the header file "somd.h" (or for C++, "somd.xh") in addition to any "<className>.h" (or "<className>.xh") header files they require from application classes. All DSOM client programs must link to the SOMobjects Toolkit library: "libsomtk.a" on AIX and "somtk.lib" on OS/2. For more information, see the topic "Compiling and linking" in Chapter 3, "Using SOM Classes in Client Programs."