Qmrtg is a free tool to help monitoring the activity of processes.
It's intended to be used with MRTG.

Qmrtg is modular. Each module carries out a different log analysis. 
A super-module lets the user easily request any analysis without to
know anything about the modules themselves.
Qmrtg has been originally written for monitoring qmail servers, but
its modules are general enough to parse any kind of log file passed
through multilog (see daemontools).

Qmrtg is a modern alternative to qmailmrtg7.

WWW: http://dev.publicshout.org/qmrtg/