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.

Monitornator - Server monitoring made simple

Pivotal - Pivotal Software provides enterprise PaaS-based solutions.

OpsDash - All-in-one solution for monitoring servers, services, uptime and databases. Curated Dashboards. Rule-based alerting.

Google App Engine - A powerful platform to build web and mobile apps that scale automatically.

NIXStats - SaaS monitoring tool for window/linux servers and websites. Think up-time robot but with more features.