Apache is a free and open-source cross-platform web server software.
Application Request Routing (ARR) is an extension to Internet Information Server (IIS), which enables an IIS server to function as a load balancer.
Azure is a cloud computing service for building, testing, deploying, and managing applications and services through Microsoft-managed data centers.
ASP.NET is an open-source, server-side web-application framework designed for web development to produce dynamic web pages.