This feature can be seen in action in Firefox, Maxthon, Avant Browser, Slim Browser, Green Browser, DeepNet Explorer, and many other freeware web browsers.
Tabs are really cool, because you don't need to open a new window for each web page that you're browsing. Each page opens in a new tab in a single main window. This prevents your taskbar from getting cluttered up, and helps you to navigate between open web pages more easily because you can see the tabs for all open pages at once.
Since tabs make a program that much easier to use, why restrict this feature only to web browsers ? Another category of applications that lends itself well to this feature are File Managers.
Many freeware dual pane file managers already exist, but, IMO, the inclusion of tabs in file managers is a really great addition. With each folder opening up in it's own tab, you can have as many folders as you want open at the same time in a single main window, and quickly navigate back and forth between them to carry out copy / paste, and other common file operations.
Here are links and screenshots of some freeware tabbed file managers:
1) xplorerÂȘ
This one is my favorite, and is what I'm currently using. This one does dual pane, as well as tabs, and has tons of other handy features like in-built file preview, mass renaming of files, shredding files, splitting files into chunks, and much more.
2) XYplorer (Formerly TrackerV3)
This is another very popular tabbed file manager. As you can see in the screenshot above, the bottom panel allows you to access a host of powerful features such as previewing files, searching for files and folders, and generating a quick report of all files in a folder, among others.
3) ExplorerXP
This a small, fast, and compact program. This one might not pack in as many features as the other 2 programs above (e.g no file preview is available), but has a useful and innovative set of features nonetheless. One unique feature of this program is Groups, which are collections of folders displayed in a small dockable window (seen at the bottom left in the screenshot above), using which users are able to quickly access folders, or drag & drop files to them.
In addition to these, there a few other useful freeware file managers, dual - pane, but not tabbed, which deserve a mention here :
Hope some of you found this information useful, and if you ever use any of these programs, leave a comment here letting me know how it went !