Webmin - Webmin is a web-based interface for system administration for Unix.
Google App Engine - A powerful platform to build web and mobile apps that scale automatically.
ClearOS - A very good alternative for Windows Server, for free
Dokku - Docker powered mini-Heroku in around 100 lines of Bash
cPanel - With its first-class support and rich feature set, cPanel & WHM has been the web hosting industry's most reliable, intuitive control panel since 1997.
Google Cloud Functions - A serverless platform for building event-based microservices.