Initialize new configurable parameters at the beginning of the configure script, in the relevant section (installation, or compilation). Later the settings for these parameters are written out to the Makefile; new parameters should also be written out to this Makefile. If the parameter is to be used as a macro within the source code, it should be written out to the file config.h, which is done by the make version command after configure has been updated and a new Makefile has been created.