The UFRaw (Unidentified Flying Raw) is a tool for reading and manipulating
raw images from digital cameras.  It supports most of the existing raw
formats (any format supported by DCRaw).  UFRaw can be used on its own or
as a Gimp plug-in.

UFRaw requires dcraw and gtkimageview; lensfun is an optional dependency
(run the build script with LENSFUN=yes if you have it installed).

However, you can add "--enable-extras" to the configure arguments in the
build script to use the included dcraw.  You'll need gtkimageview if you
want to include the image preview window.  You can build ufraw without 
gtkimageview (run the build script with GTK=no), but you'll only have command 
line interface to UFRaw.