The Green Monster!

Netbeans never ceases to amaze me.
I just moved a project from my Ubuntu machine to my Fedora machine.  I did a straight copy since I have the same account under the same directory structure.
Things work fine.  However, every file that I open in the editor window displays a solid green line in the left edge of the editor window and a number of dashed lines which are bunched close together in the right edge.
If I point my mouse cursor to either left edge or the right edge, it shows the number of lines in a tool-tip (or pop-up) which says something like (91 lines added).  So this is for the account_controller.rb file which has 91 lines.  Similarly, it is doing that for every single file regardless of the type of file.
Other projects that I have created natively on the Fedora machine do not display this behavior.  Is there a reason why Netbeans is doing this?
Bharat