Microsoft Application Request Routing (ARR) for IIS 7 and above is a proxy-based routing module that forwards HTTP requests to content servers based on HTTP headers, server variables, and load balance algorithms. ARR can be used to:
- Increase application availability and scalability.
 - Better utilize content server resources.
 - Facilitate application deployment including pilot management and A/B testing.
 - Lower management costs and create opportunities for shared hosters.
 
The Application Request Routing installer package contains the following components:
- Microsoft URL Rewrite Module for IIS.
 - Microsoft Web Farm Management Version 1 for IIS.
 - Microsoft Application Request Routing Version 1 for IIS.
 - Microsoft External Cache Version 1 for IIS.
 
Microsoft Application Request Routing Version 2.5 for IIS 7 (x64)
Microsoft Application Request Routing Version 2.5 for IIS 7 (x86)
