export SOURCE_DIR=/usr/src : This command allows you to specify which directory is your source directory by replacing /usr/src. --with-mozilla-libs=/opt/mozilla/lib/mozilla-&mozilla-version; : This command directs galeon's configure script to the mozilla libraries. --with-mozilla-includes=$SOURCE_DIR/mozilla/dist/include : This command sets the location of the mozilla headers. --disable-werror : This command is required for GCC-&gcc-version; compatibility.