This is nautilus 2.6.2, the file manager for the Gnome 2 desktop.

Major changes since 2.6.1 are:
* Accessibility/keynav/theming fixes
* Leak fixes
* .desktop file updates
* Fixed help buttons in the preferences dialog 
* Portability fix
* Use initial click position to anchor icon dnd
* Crash fix in the file properties dialog
* Don't overlap the close icon and text label when the sidepane
  is very small.