Back when OS X was first released as a beta product, applications were displayed one at a time. Even though multiple applications could be running at the same time, only one would be visible on the desktop. This was called single-application mode. When you clicked on the icon of any running application in the Dock, its windows would spring to life, while the windows of the previously active application would be sucked back down into the Dock.
Single-application mode kept desktop space uncluttered, but it made working with multiple applications a pain in the windows. For that reason, Apple presented the first release version of OS X with a multi-application mode as the default behavior for the Finder and its desktop. This is, of course, the way we have all become used to working with OS X and its applications: having the windows of multiple applications open at the same time.
However, there is something to be said for the clean, single-application interface of single-application mode, especially for those working with smaller displays. If you would like to try out single-application mode, it’s still available via a Terminal command. Here’s how to activate it.
Enable Single-Application Mode in Snow Leopard
- Launch Terminal, located at /Applications/Utilities.
- Type or copy/paste the following commands into the Terminal window. Press the return key after you enter each line of text. Note: There are only two lines of text below. Depending on the size of your browser’s window, the lines could be wrapping and appearing as more than two lines. Be sure to enter them as two single lines.
defaults write com.apple.dock single-app -bool true
killall Dock
Snow Leopard’s single-application mode is tied to the Dock, which means that switching from one application to another by clicking on Dock icons will invoke single-application mode. However, if you have multiple applications and multiple application windows open, and switch from one application to another by clicking on one of its windows, single-application mode will not be activated.
Enable Multi-Application Mode in Snow Leopard
You can return to the default multi-application mode with Terminal.
- Launch Terminal, located at /Applications/Utilities.
- Type or copy/paste the following commands into the Terminal window. Press the return key after you enter each line of text. Note: There are only two lines of text below. Depending on the size of your browser’s window, the lines could be wrapping and appearing as more than two lines. Be sure to enter them as two single lines.
defaults write com.apple.dock single-app -bool false
killall Dock
