There is no shortage of file managers for Linux but each one seem to be incomplete in one way or another - e.g., interface is not pretty, lacking some functionality, not simple enough or not powerful enough.

Another file manager, named Dolphin, will soon be released with KDE 4 in an attempt to provide features that users are looking for. Some of its general features are:

1. Renaming of a variable number of selected items in one step.
2. The columns of the view mode 'Details' are automatically expanded to the available width of the window.
3. Information dialogs having only one 'OK' button like e. g. "Access denied to /opt/kde3." have been banned from Dolphin. Instead of interrupting the work flow of the user such kind of information is shown inside a custom implementation of the status bar. To assure that the user does not miss any important information a recognizable but not a bothering animation is done.
4. Undo/Redo functionality.
5. Network transparency (thanks to KDE's KIO slaves!).
6. Support of service menus from Konqueror. To use the service menus they must be copied from their current location (e. g. /opt/kde3/share/apps/konqueror/servicemenus/) to the service menus folder used by Dolphin (e. g. /opt/kde3/share/apps/dolphin/servicemenus). As most linux distributions overloaded the service menu folder from Konqueror by a huge number of service menus, it has been decided not to use the Konqueror service menus directly.

IMHO, this is one pretty and feature-rich file manager. Definitely a must-have if you are using KDE. Here's ArsTechnica's First Look.