Redis - Redis is an open source in-memory data structure project implementing a distributed, in-memory key-value database with optional durability.
Apache Tomcat - An open source software implementation of the Java Servlet and JavaServer Pages technologies
memcached - High-performance, distributed memory object caching system
Microsoft IIS - Internet Information Services is a web server for Microsoft Windows
MongoDB - MongoDB (from "humongous") is a scalable, high-performance NoSQL database.
Apache HTTP Server - Apache httpd has been the most popular web server on the Internet since April 1996