The source on that page is for the Nautilus (GNOME File Browser) extension that adds right click menus and special icons to the file browser and "dropbox" a com

The source on that page is for the Nautilus (GNOME File Browser) extension that adds right click menus and special icons to the file browser and "dropbox" a command line client for talking to the dropbox daemon in the same way as the Nautilus extension. The secret sauce is dropboxd which is not open source.