InfoWorld's 2009 Bossie Awards
Open source enterprise monitoring leaders OpenNMS and Zenoss share a number of advanced features that separate them from the likes of Nagios and Cacti and approach the high-end commercial offerings from HP, IBM, and CA. Whereas Zenoss has a broader set of features, thanks to proprietary modules, OpenNMS is purely open source. Customers get all of its advanced functionality free, paying only for support or training services. Read the review.