In response to the thread about the look of Windows7, I am providing some screenshots of what OSX looks like on my MacBookPro.
The desktop. Mounted drives appear here, and are normally aligned to the right. The first one, Slartibartfast, is my internal drive. The other three are externals - one is for backup, the other two are storage. Also some frequently accessed folders are also available. The bottom row is the Dock, which contains links to frequently used applications. You choose which to put there and which to leave off - I like to keep my Dock full. Notice that the dock icons seem to sit on a reflective shelf, and they have a blue light on the shelf that tells you what applications are running. Even though OSX has Spaces, which is like multiple desktops in Gnome or KDE, apps that are running on another workspace are lit up in the Dock. Apps that are minimized get iconized right next to the trash can - that's a browser window you see down there. There are 2 folders next to the browser icon, separated from the Dock icons by a dashed white line. Those are folder stacks. My documents folder and my downloads folder are there, and I can open them temporarily simply by hovering over the icon with the mouse. Top of the screen is the menu bar. On the left are the usual dropdowns, which change depending on which application is running. On the right are system things - from L to R, I have: iTunes controller, a mainboard temp gauge, Time Machine icon, AppleScript editor, Spaces, bluetooth, Aiport Wireless, volume, keyboard language, battery power, time, and Spotlight (finds files).
http://www.triple-bypass.net/download/screenshots/screencap-desktop.pngThe System Preferences window. When you click on one of these items, the dialog appears in the same window, and a "Show All" button appears, which takes you back to this screen. Background left in so that you can see the window shadow behind it. Note the section at the bottom, labeled "Others" - that is where preferences from non-system programs can be added. It works best for background daemons or utilities that don't have windows of their own.
http://www.triple-bypass.net/download/screenshots/screencap-sysprefs.pngA terminal window. The power of *nix from your Mac desktop. There are like 6 different foreground/background choices available, I happen to like this combination. Of course you choose from infinite color combos if you write your own bash profile. In case you can't tell, the command currently running is "man ls". Background left in so you can see the window shadow behind it. I have to admit I am not so fond of how the terminal font renders bold caps - fortunately, it doesn't happen often.
http://www.triple-bypass.net/download/screenshots/screencap-terminal.pngExpose in action. Expose is a neat program that allows you to keep track of your open windows. It works off of customizable hot corners. If I drag to the upper right corner, Expose will move all windows out of the way and show me the desktop. If I move to the lower right hand corner, Expose will shrink down all the open Windows and fit them on one page - which makes it possible to grab windows from behind other windows without minimizing. Lower left corner brings up the Dashboard. I have upper left set to do nothing. The screenshot shows a browser window, the System Preferences window, and a terminal window all being simultaneously revealed by Expose. You can always tell Expose is working because your wallpaper goes all dark, as evidenced in the image.
http://www.triple-bypass.net/download/screenshots/screencap-expose.pngAnd the Dashboard. As I mentioned above, mousing to the lower left corner causes Expose to activate the Dashboard. Dashboard is a collection of interactive applets (called widgets), just like those things on the Vista desktop (but predating them by over 5 years). You can have as many items in there as you like, but I just have a few. There's a weather thing, a calendar, an iTunes controller, a units converter, a scientific calendar, and a hex color converter. The Apple logo is also a Dashboard widget, but all it does is put a random historical Apple logo in your Dashboard. Of course weather apps and iTunes controllers and hex converters and unit converters and calculators are all available as stand-alone apps (calculator is actually a system utility). But this takes the functionality of standalone apps and puts them in a nice little drawer where I can get to them fast, simply by moving the mouse pointer. Notice that the entire desktop, including the browser window, have darkened, to focus on the Dashboard widgets. Also notice the white symbol in the lower left hand corner - that's the dashboard control button - click it, and a widget editor appears.
http://www.triple-bypass.net/download/screenshots/screencap-dashboard.pngAnyway, those are some of the nicer points of the system. Not all of these effects were available in all versions of OSX - Expose first appeared in 10.3 Panther, Dashboard in 10.4 Tiger, and Spaces in 10.5 Leopard. The Dock shelf is also a new feature in Leopard. But most elements of the graphical interface, including the shadows, window decorations, and system cohesion have been around since the beginning.
FYI, the web browser I am running in these screenshots is Shiretoko, which is the code name of Firefox 3.1. One of the reasons Firefox rules is that I can run Shiretoko and Firefox alongside each other. Not at the same time, but I can close one and open the other one, and the bookmarks and history are up to date. I don't like the basic Firefox theme for OSX, so I use a theme called Caminofox, which brings all the graphical elements of Camino to Firefox.
Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1b3pre) Gecko/20090227 Shiretoko/3.1b3pre