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.
Sitecake - Drag and drop CMS for HTML websites. It's flat file CMS so it's pretty fast.
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.
Anchor CMS - Free and lightweight blogging system
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Textpattern - Textpattern is an elegant content management system that is free, open source software.