When you select an application -- either from the dock or by using the application switcher key combination (command/Apple-tab) -- whose front-most window is in a different Space than the one you're currently using, you will automatically be switched to the appropriate Space. It's a little unclear how Leopard will determine which window is front-most if an application contains windows in multiple spaces. It seems logical that the most recently used window will be selected, much as the application switcher always displays the most recently used application as the next choice. But for those kinds of details, we'll have to wait on Jobs and company for more information.

Expose will also be closely integrated with Spaces. This means that you will be able to see all windows in all spaces using Expose, offering a quick and easy way to locate and switch to specific windows among multiple Spaces.

It also appears that the finder, or more accurately, the finder items on the desktop (as opposed to finder windows) will display consistently across all spaces. This makes sense because you typically place items on the desktop that you want convenient access to. It also provides easy access to all mounted hard drives, optical disks and share points (assuming you have the finder set to display them on the desktop).

Configuring Spaces

Spaces will be configured using System Preferences. It appears the feature will actually be built into the same pane that now handles Dashboard and Expose settings. By default, four Spaces will be available, but users can define more Spaces if they need them by adding rows and/or columns to the virtual map. Exactly how many Spaces can be defined is still unclear -- some Mac users have suggested that the number will be limited to nine; others say it could be more than that. (While technically possible, having more than nine Spaces would push the limits of ease of use.)