Google App Engine - A powerful platform to build web and mobile apps that scale automatically.
Apache Tomcat - An open source software implementation of the Java Servlet and JavaServer Pages technologies
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.
Microsoft IIS - Internet Information Services is a web server for Microsoft Windows
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.
Apache HTTP Server - Apache httpd has been the most popular web server on the Internet since April 1996