OpenSLAM

This is a map of the University of Freiburg Campus generated with Gmapping. Conveniently enough, a wrapper has been made for GMapping to work with ROS and someone has written a tutorial on it.

This image shows the results of the TreeMap Algorithm. This has not been ported to ROS, yet.

Code for these and many more simultaneous localization and mapping (SLAM) algorithms are available at OpenSLAM.org.