-
http://info.iet.unipi.it/~luigi/polling
-
http://l7-filter.sourceforge.net/index.php.fr
-
http://www.dragonflybsd.org/main
-
http://www.onlamp.com/pub/a/bsd/2004/07/01/freesbie.html
-
http://modeemi.cs.tut.fi/~tuomov/pwm/prog/workspace_indicator
-
http://www.openbsd.org/faq/pf
-
http://x.guimard.free.fr/postfix