Although most users will simply link to one or other of the GTS-GRAL libraries, it is perhaps as well to mention that there is a fairly straight-forward procedure to re-configure these libraries to add or omit drivers. In both GKSGRAL and GKSGRAL-3D all driver code is accessed via the routine GKDDLK. Thus, in order to change the configuration, it is only necessary to edit and re-compile this routine. Of course, the corresponding driver routines must be added to/deleted from the library. Where access to GKDDLK is not available, it is possible to use the non-shared library version and to link to dummy versions of the un-used drivers.
Some of the drivers may make use of low-level proprietary software, such as VERSAPLOT, which cannot be included in the library as a separate licence is required. Installations which configure drivers of this type, but which do not have the low level software, may wish to provide a dummy library in order to avoid a long list of unresolved external references.