My favourite of these tools in Centreon. It is an unholy mix of just about everything (nagios snmptraptranslator etc) and would be awesome if only a few more opensource developers would work on it.
"The community simply isn’t responsible enough to say, “No, this won’t work, re-implement it.” A company with QA is."
Try as I might, I cannot help but to agree with that statement, especially when the stagnant state of Nagios, Cacti, and Munin are concerned.