The famous file manager in KDE 3.x is the "Konqueror", you can use konqueror for file manager, browsing and viewing the document like PDF and DVI. Everybody already know about it, and sure will use it in KDE 3.x. What about file manager in KDE 4? You should hear first!, "Dolphin" is the answer! Actually in KDE 4, Konqueror file manager will replace by Dolphin, but you still can use konqueror for file manager and browsing. Dolphin is the most stable application in KDE 4, have many feature inside, and sure you can easily manage your file in your computer. You want to know how the Dolphin look like?