You can toggle display between users' command or idle time. You can watch processes tree, navigate in it and send INT and KILL signals. Ncurses library and read access to utmp, wtmp. It is a daemon that waits for incoming tcp connections and tries to recognize TCP and UDP port scans. Scandetd will also attempt to recognize OS fingerprinting probes.
Program can send email to system administrator.
All things like trusted IP addresses, port ranges to ignore, IP resolving, count threshold, email address, syslog facility etc. are located in a configuration file. Program works ONLY under Linux at the moment. More info about program is here . See notifyrc.sample for example. It should be self explanatory.