The ExMiller component is a file and folder view control that uses the Miller Columns visualization technique to present system directories and files. Miller Columns, also known as Cascading Lists, are a browsing method for tree structures that allows multiple hierarchy levels to remain open simultaneously, providing a clear visual representation of the current location within the structure. This approach is closely related to earlier concepts used in the Smalltalk browser and was independently developed by Mark S. Miller in 1980 at Yale University. Today, Miller Columns are widely recognized as the “Columns View” in macOS Finder and the “Browser” view in iTunes.