Other information sources

• ATV Image Viewer
  http://www.physics.uci.edu/ barth/atv/

• IDL Astronomy Library
  http://idlastro.gsfc.nasa.gov/homepage.html

• HEASOFT
  http://heasarc.gsfc.nasa.gov/docs/software/lheasoft/

• XDialog
  http://xdialog.free.fr/

• GTK+
  http://www.gtk.org/