General Features:

renaming of single files
renaming of complete directories
recursive directory scanning with Wildcards (e.g. *.mp3)
renaming of directory names
renaming of huge numbers of files (more than 10.000)
renaming of filename and extension
expandable by the use of a open plugin architecture
Konqueror integration
Krusader integration
International: English, German, Spanish, French, Japanese, Italian, Chinese
Preview for all image formats supported by KDE and some other file formats
Two easy to use GUI modes (tabbed and wizard like)

possible actions:

rename files
copy files
move files
Undo Renaming (via BASH Script)
create shortcuts
overwrite files

Rename Features:

change order of files
sort files in directories
search and replace parts of filename (multiple)
search and replace using regular expressions
manual modifying of the resulting filename
change filesname or extension in:
lower case (e.g. krename.png)
caps (e.g. KRENAME.PNG)
first character in word to caps (e.g. Krename.png)
numbering of files (start,steps,skips definable)
add the current Date and time to a filename
using substrings of the old filename
create subdirectories while renaming

KDE Plugins

MP3-Info

XBM-Info

DEB Stats

AU-Info

PDF-Info

RPM Stats

Truevision Targa Info

JPEG-EXIF-Info

Catalogue-Information

Font-Information

BMP-Info

WAV-Info

PostScript-Info

vCard-Info

C++-Header-Info

E-Mail Info

Diff-Statistics

C++-Info

AVI-Info

TIFF Dateien Metainformation

Berechtigungen

PNG-Info

ICO-Info

OGG-Info

... and a lot more plugins