Yesterday Zenoss released Zenoss Core 4.2.4. This is mostly a bugfix release, so lets start with the list of 175 bugfixes (JIRA/Requires Login). This represents 7 months worth of significant effort in our continued work towards open source software which is strong, dependable, QA'd, and functional. We hope you enjoy it.
If you're doing a fresh install, instructions are here. If you're upgrading from Core 4.2.0 or 4.2.3, Core 4.2.4 does require redis which can be installed from epel (yum --enablerepo=epel install redis). Please stop Zenoss before upgrading, and use rpm, not yum to upgrade your Zenoss installation. Zenoss will process the upgrade on restart, and this may take several minutes.
Zenoss supports a large, and expanding list of ZenPacks to extend both monitoring and functionality. If you need help, Zenoss Core is supported by a large friendly Community of people, and getting help is easy.
Just so you know, Zenoss is awesome, and I'm not the only one saying it. Check out what Network World recently had to say about Zenoss Core.