When I switched from MacOSX to Windows some years ago (long story), one of the features I most missed in Windows was the ability to display the Finder (the Mac's file manager, like Windows Explorer) by "Column View".
Anyone who has ever used a Mac with OSX will agree, I think, how handy column view is. The way column view works in the Finder is like this:
within a single window, each folder can be displayed as a column with all the contents of that folder displayed. Clicking on any folder within that column opens immediately a parallel column to the right and so on. Also, if the column's root folder is itself a buried subfolder, immediately beginning at the left, all the parent folders will each be displayed in columns all the way back to a root column, which is the equivalent of WE's tree. When one clicks on a file in a column, the finder can be configured to open a preview column which will display information about that file. Items can be dragged and dropped between columns and the columns can be made to auto-open to a set width or to the width of the filenames within. Obviously, this works like columnar 'breadcrumbs', where every column corresponds to a part of the breadcrumb trail. It was/(is?) even possible by using the option button and mouse to drag selected columns to preferred widths, all different if so wished, and have the Finder remember those settings each time that folder was opened or navigated to in column view.
This was one of the best - of very few, admittedly - of the good features of the Mac Finder that I remember, certainly the most useful, and I have often wondered if a similar arrangement could be ported to the Windows Explorer, say as an extension.
See here for some shots of column view demonstrated (about half-way down tha page):