GroundWork retains the nearly limitless flexibility of its underlying Nagios-based monitoring engine while adding a much more functional AJAX-based Web portal and configuration interface. Given that it is based on Nagios, it retains access to the multitude of available Nagios plug-ins and extensions, making it very likely that anything an average business has on its network can be monitored.
Hyperic is a purpose-built application monitoring package that can monitor very complex systems from the Web server, through the application server, to the database engine, and all the way down through the hardware and out into the network. All of this is done with an eye toward end-to-end performance. Hyperic doesn’t have the kind of hardware device support or brass-tacks infrastructure views that either GroundWork or Zenoss do, but it makes up for that by being able to track and interrelate resources that are required for delivering a given application infrastructure in a very comprehensive manner.
Zenoss is one of a very few packages that has attempted to completely re-imagine the makeup of an enterprise-wide monitoring package. It has been designed from scratch to be fully unified and internally seamless. At the same time, care has been taken to retain the same support base that Nagios enjoys by including built-in support for Nagios plug-ins while also offering powerful monitor generation abilities. Zenoss’s Ajax Web interface is one of the easiest to navigate and manipulate, and installation and upgrades are easy even for a Linux or Unix neophyte.
Another project to keep an eye on is OpenQRM, backed by Qlusters. OpenQRM doesn't fall directly within the enterprise monitoring space, but is an open source provisioning solution that is squaring off against much larger closed-source rivals. OpenQRM provides a means to dynamically scale available server capacity based on load characteristics. It can monitor server load and deploy additional virtual servers into a virtual infrastructure as they are needed. It is compatible with VMware and Xen and fully supports automatic provisioning and monitoring of Linux servers, with some limited support for Windows VMs.
These four products are just a sampling of what’s out there now and is a taste of what’s to come. It is no longer a question whether open source monitoring and management solutions will displace the large, closed-source gorillas that dominate the market today, but how long the gorillas can hold on.