File Juicer

File Juicer til Mac OS X

Search & Extract

Images

jpg jpeg 2000 gif png pdf wmf emf tiff eps pict bmp

Video

mov mpeg avi wmv

Sound

mp3 wav System 7 au aiff

Text

ascii rtf html

From:

avi cab cache chm dmg doc emlx exe ithmb m4p mht mp3 pdf pps ppt raw swf wps xls zip and other formats

rdf - Resource Description Framework files

RDF files are plain text formatted files which look a lot like HTML.
You can open RDF files with a text editor like TextEdit. RDF files contain descriptions of other files, not the files themselves but links to them.

OReilly about RDF
Wikipedia about RDF