All popular clients use GNU autoconf and GNU automake, thus come with a configure script. Read the installation instructions after you unpack the sources. Be sure you have the required libraries in order to compile. Doing cd sources; mkdir objdir; cd objdir; ../configure --help; ../configure your_options_here; make; make install (or make install_strip) > ~/sources_install.log is the right procedure. Also note that for ircII, EPIC, and BitchX you should really edit include/config.h to suit your needs.