Project Manager -the utility for organisation of files and work with them in 3ds Max.
It help you with cataloging and using in your projects of a bitmaps, library of models and materials, also IES and HDRI files.
The organization system allows the to keep references to the directory in different directories without duplication of folders on your hard drive.
For example you can put same folder of 3d models "Classic Chandeliers" in the catalog "Classics" and catalog "Lamps".
For more convenient job with libraries all information is presented in the thumbnails view.