The rqt tools (ROS Qt GUI toolkit) that are part of ROS allow graphical representations of ROS nodes, topics, messages, and other information. The ROS wiki lists many of the possible tools that are added to the rqt screen as plugins: http://wiki.ros.org/rqt/Plugins.
The ROS tutorial on topics also describes some of the features of the rqt tools at: http://wiki.ros.org/ROS/Tutorials/UnderstandingTopics
One of the common uses of rqt is to view the nodes and topics that are active. Bring the TurtleBot up with minimal launch as previously described. Then, on the remote computer, issue the following command:
Select the top-left box, Nodes/Topics (all). The following screenshot of
rqt_graph shows the nodes that ...