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.
Qualys - Qualys helps your business automate the full spectrum of auditing, compliance and protection of your IT systems and web applications.
AppDynamics - Get real-time insight from your apps using Application Performance Management—how they’re being used, how they’re performing, where they need help.
Trend Micro Deep Security - Excellent hybrid cloud security doesn't require your business to sacrifice operational performance. Trend Micro lets you keep business moving securely.
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Sysdig - Sysdig is an open source, system-level exploration that capture system state and activity from a running Linux instance, then save, filter and analyze.