.NET Dependency Walker is free for non-commercial use. However if you use the application in a commercial environment then you must license the Professional edition.
Licensing is per-user for a single major version and includes all updates. As a licensed user you get access to a couple of useful features not available in the free edition and priority support.
|Explore Dependent Assemblies|
|Explore Dependent Native Libraries|
|See Native Calls|
|See Assembly Types|
|See Forward Types|
|See Imported Types|
|Export Dependencies List|
|List Native Libraries|
|Export Native Libraries List|
* Discounts are available during checkout on purchases of 5 or more licenses.