I’ve been using OS 10.5 Leopard for a few days now, and I really like the improvements over OS 10.4 Tiger, but one of my favourite features of the new cat is the virtual desktop application Spaces. Virtual desktops have been a standard in the Linux/Unix world for a long time, and there are even a few incarnations for the Mac.

The big difference between the implementation of virtual desktops in Linux and the Mac is the Mac’s application/document model. On Linux (and Windows), when you have an app like Firefox open, it’s window is kind of like an instance of the program. But, on the Mac, each window is just a document. Firefox can be running with no windows open, or it can be running with a dozen windows open, but only one icon will appear in the dock.

This has many advantages, but when it comes to virtual desktops, it’s a bit of a limiting factor. If I have Firefox open in Space 1, for instance (no pun intended here), and I move to Space 2 and click on the Firefox icon in the dock, I automatically switch back to Space 1 because that’s where the program was opened. The app is assigned to a Space instead of the window being assigned to a Space like in Linux.

This happens because clicking on an app’s icon in the dock doesn’t launch a new window. It just brings the app into focus. In Windows or Linux, this causes another instance of the program to open.

To get around this annoyance, you have to control-click or right-click on the dock icon, and choose to open a new window in the new Space. Once you’ve done that, things seem to work more as you would expect them to. When you click on the dock icon, and the app isn’t already in focus, it will gain focus. If it is in focus, the window in the other Space will gain focus, and that Space is shown.

Overall, Spaces is a welcome addition to OS X. I think it should have been there all along. I’m also, sure that somebody will come up with an app that addresses this little annoyance.

::EDIT::
The control-click on the dock icon does not work with Firefox, but it does work with Safari. Sorry for the confusion.