This 3ds Max blog is a team effort by Nicolas Holst, Lee Montgomery, Vishnu Ramdass and Anil Choudhary.
MDL stands for: Material Definition Language, this is an initiative by nVidia to standardize physically based material designs in a common format.
In your rush to get going with 3ds Max 2016 you just clicked on Classic but now you want Design (or the other way around).
Link to the hires Populate data for 3ds Max 2016
Links to the download page with the product help installers.
Quick workaround to get DBR working in 3ds Max 2016
New feature in 3ds Max 2016: mental ray Light Importance Sampling
How do you add a scrollbar to a rollout using Maxscript
In this second post we'll look at the scanline and mental ray renderers and how many cores they can use.