| Attribute / Project | [OpenNMS](https://www.opennms.org/) | [Nagios](http://www.nagios.org/) | [Zenoss](http://www.zenoss.org/) | Hyperic | [Zabbix](http://www.zabbix.com/) |
|---|
| Peer Support |
| Forum |  |  |  |  |  |
| Mailing list |  |  |  |  |  |
| Commercial Support |
| Support contract |  |  |  |  |  |
| Training |  |  |  |  |  |
| Consulting |  |  |  |  |  |
| Learning resources |
| Blog |  |  |  |  |  |
| Book(s) |  |  |  |  |  |
**Update 1**: Zenoss has a forum / mailing list system. Both interoperate together so a post to one goes automatically into the other
