This is nautilus 2.9.91, the file manager for the Gnome 2 desktop.

Major changes in 2.9.91 are:
* Fix some crashes
* Don't pop up mozilla dnd ask dialog under windows
* Change the look of the path button to make it easier to find
* Some changes to the look/text of the progress dialog
* Fix panel size detection on 64bit machines
* Allow open with menu on folders