What installation software does sql server 2008 R2 use?

I really like the design of the installer that comes with SQL Server 2008 R2. (I think its the same in R1 also, but not sure).

Does anyone know what installer / setup technology was used to create it? I'd like to do something similar for my 开发者_StackOverflowown application.

I don't think it's Wix, Wise or InstallShield, but perhaps I'm mistaken.