Ristretto is a fast and lightweight picture-viewer for the Xfce desktop environment.
Gtk+ (2.20.x or higher)
libxfce4util (4.8.0 or higher)
libxfce4ui (4.8.0 or higher)
libexif (0.6.0 or higher)
libdbus-glib (0.34 or higher)
libexo (0.4.0 or higher)
xfconf (4.8.0 or higher)
The latest release of ristretto can be downloaded here.
Current version is 0.3.0 (sha1)
You can also check out the latest bleeding-edge code from the Goodies GIT Repository like so:
git clone git://git.xfce.org/apps/ristretto master
You can view the GIT source tree online as well.