Apache Tomcat - An open source software implementation of the Java Servlet and JavaServer Pages technologies

FastMail - Email, calendars, and contacts to highest standards of security, privacy and reliability.

nginx - A high performance free open source web server powering busiest sites on the Internet.

Zoho Mail - Zoho Mail is a secure, encrypted, and enterprise-ready email solution, a suite of apps tailor-made for your organization's needs.

vCenter Server - IaaS platform for managing and deploying virtual machines

QQ Mail - QQ Mail is an enterprise email solution from Tencent.