ISPConfig - ISPConfig 3 is an open source hosting control panel for Linux.
ServerSuit - ServerSuit is a browser based program that enables remote Linux administration, monitoring, website hosting, and server setup automation.
RedGate SQL Monitor - SQL Monitor helps you and your team find issues – before they become problems
CloudStick.io - CloudStick is an All-in-one cloud-based control panel designed to manage servers from Digital Ocean, Linode, AWS, Google Cloud, Vultr, or any KVM or Dedicated servers you prefer. Let's deploy together!
Nagios - Complete monitoring and alerting for servers, switches, applications, and services
ServerPilot.io - Centralized hosting control panel for Wordpress and PHP web sites