Actipro Shell controls allow for easy folder and file browsing. While the product comes packed with a pre-built implementation for the Windows shell that mimics Windows Explorer, the controls are fully customizable, allowing you to filter or change the folders/files presented. Or build your own shell service to support other files systems, such the remote side for a FTP client.
All of the UI found in the Shell controls is native WPF, even the context menus. Unlike competitive products with interop-based user interfaces, the Actipro Shell controls don't have any airspace or focus issues, and every bit of UI can be fully-themed or even customized with XAML data templates.