Cloud Foundry - Cloud Foundry is an open platform as a service, providing a choice of clouds, developer frameworks and application services, making it faster and easier to build, test, deploy and scale applications from an IDE or the command line.
Google App Engine - A powerful platform to build web and mobile apps that scale automatically.
browserling - Live interactive cross-browser testing from your browser.
Heroku - Agile deployment platform for Ruby, Node.js, Clojure, Java, Python, and Scala. Setup takes only minutes and deploys are instant through git. Leave tedious server maintenance to Heroku and focus on your code.
Salesforce Platform - Salesforce Platform is a comprehensive PaaS solution that paves the way for the developers to test, build, and mitigate the issues in the cloud application before the final deployment.
DigitalOcean - Simplifying cloud hosting. Deploy an SSD cloud server in 55 seconds.