1.3.2 Optional

• libnftnl (optionally on Linux 3.x for autonat support)
• libnpf (when OPTION npf is enabled in NetBSD kernel, for autonat support)
• GNU m4 (only used if recompiling one of the generated sources or after "make clean")
• GNU make (might be required to take advantage of extensions on some platforms)
• Perl package X11::Protocol (needed if using static keymap under X11, e.g., when using Wine or some other emulator under X that cannot access Xlib)