BOINC - BOINC is an open-source software platform for computing using volunteered resources
Google App Engine - A powerful platform to build web and mobile apps that scale automatically.
Apache Mesos - Apache Mesos abstracts resources away from machines, enabling fault-tolerant and elastic distributed systems to easily be built and run effectively.
Dokku - Docker powered mini-Heroku in around 100 lines of Bash
JPPF - The open source grid computing solution.
Google Cloud Functions - A serverless platform for building event-based microservices.