Miller columns

A Miller Column browser as implemented by GNUstep. It incorporates a Shelf.

Miller columns are a browsing/visualization technique that can be applied to tree structures. The columns allow multiple levels of the hierarchy to be open at once, and provide a visual representation of the current location. It is closely related to techniques used earlier in the Smalltalk browser, but was independently invented by Mark S. Miller in 1980 at Yale University^{[citation needed]}. The technique was then used at Project Xanadu, Datapoint, and NeXT.

While at Datapoint, Miller generalized the technique to browse directed graphs with labeled nodes and directed graphs with labeled nodes and arcs^{[citation needed]}. In all cases, the technique is appropriate only for structures with high degree (large fanout). For low-degree structures, outline editors or graph viewers are more effective.

Popularizing the column browser

Miller columns are most well known today as the "columns" view of the Mac OS X Finder, as well as the "Browser" view in iTunes. The columns in Finder descend directly from the NeXTSTEP File Viewer's use of Miller columns going back to 1986. The GNUstep project continues to offer a Miller column browser that closely follows the NeXT approach, bringing the advantages of a Column browser to Linux, BSD, and other operating systems with large tree structures. The iPod's browsing of categories and audio file tag attributes is reminiscent of column browsing, but only one column is visible at a time. Many software music players implement a "tag browsing" feature that utilizes Miller columns. An implementation of a columns view is also available in the Dolphin file manager in KDE 4.

See also

• Shelf: NeXT GUI element that can be combined with columns to make a file manager.
• Some Microsoft Windows file managers such as CubicExplorer and UltraExplorer use this technique with the name Drop Stack.

External links

• FSViewer a GNU file system viewer similar to NeXT's Workspace Manager, with code
• Greg's Browser a NeXT-inspired column browser for the Mac OS that predates Mac OS X
• NSBrowser The Cocoa/NextStep class that represents a generalized Miller Column widget
• Path Finder an alternative file system viewer for the OS X Finder
• Ranger a console file manager for Linux written in Python, inspired by Miller columns
• RBrowser a Miller Column FTP browser that started on NeXTSTEP
• UltraExplorer a file manager for Microsoft Windows that has a column mode similar to Mac OS X column view
  • Video example of UltraExplorer for Windows