The nav_view package has been replaced by rviz. See this tutorial for information on using rviz with the navigation stack. For computers with underpowered or no graphics cards, rviz may not work well because of its reliance on the ogre rendering engine. Light-weight alternatives can be found below:

Wiki: nav_view (last edited 2011-10-03 18:06:40 by EitanMarderEppstein)