Zabbix - Track, record, alert and visualize performance and availability of IT resources
Ansible - Radically simple configuration-management, application deployment, task-execution, and multi-node orchestration engine
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
Chef - Automation for all of your technology. Overcome the complexity and rapidly ship your infrastructure and apps anywhere with automation.
Prometheus - An open-source systems monitoring and alerting toolkit.
Puppet Enterprise - Get started with Puppet Enterprise, or upgrade or expand.