This is a very interesting stuff for managing scalable web farms based on your own IIS servers, in a better way .

The Microsoft Web Farm Framework is a free, fully supported, Microsoft product that enables you to easily provision and mange a farm of web servers.  It enables you to automate the installation and configuration of platform components across the server farm, and enables you to automatically synchronize and deploy ASP.NET applications across them.

It supports integration with load balancers, and enables you to automate updates across your servers so that your site/application is never down or unavailable to customers (it can automatically pull servers one-at-a-time out of the load balancer rotation, update them, and then inject them back into rotation).

You can create a web farm like the following (or many more servers, of course):

Underneath it can be relying on the (free) IIS Application Request Routing (ARR) module,  Microsoft NLB (Network Load Balancing) or even Hardware load balancers.

See how simple is to create a WebFarm:

 

For more info see:

http://www.iis.net/download/WebFarmFramework

and:

Aditionally, info about IIS Application Request Routing (ARR) module and Microsoft NLB (Network Load Balancing)

http://learn.iis.net/page.aspx/511/achieving-high-availability-and-scalability---arr-and-nlb/