What's New in Mac OS X 10.3 Panther
Disclaimer: although I am an Apple Certified Trainer by day, this guide is not endorsed by or affiliated with Apple in any way, nor is it indicative of future Apple Training courses. It is based entirely on my own personal experience and research. Any inaccuracies are my fault. Comments and corrections welcome at firstname.lastname@example.org.
Managing Users: the new Accounts pane
The Accounts pane of System Preferences is where you manage users, and it's gotten a serious overhaul in Mac OS X 10.3. Partly to make room for new functionality (like fast user switching and encrypted home directories), and partly to streamline the existing features of adding, editing, and deleting users.
Mac OS 9 had a Startup Items folder in the System Folder, which contains aliases of applications that ran immediately after the Finder came up. Mac OS X kept the concept but renamed it "Login Items", since the Finder doesn't get launched until after a user logs in. Mac OS X 10.3 keeps the concept but renames it "Startup Items" again.
You delete a user by selecting the user from the user list and clicking the little "-" sign at the bottom of the user list. When you delete a user, Mac OS X 10.2 saved the contents of their home directory to a disk image. Mac OS X 10.3 has an option to skip this step. Clicking "Delete immediately" in the delete configuration window will delete the user and delete the contents of their home directory. Clicking "OK" in the delete confirmation window will delete the user and save the contents of their home directory to a disk image and put it in
Standard users (who do not have administrative rights) are normally restricted to running applications and modifying files in their own home directory, but they can have additional limitations. In Mac OS X 10.2, this was called "Capabilities". The functionality is the same, only the interface has changed.
By selecting "Some Limits" in the Limitations tab, you can prevent the user from opening System Preferences at all (so they won't even have access to user-specific preference panes, like keyboard and mouse settings), prevent them from modifying their own dock, prevent them from changing their own password, and prevent them from burning CDs. You can also specify exactly which applications they are allowed to run. If they attempt to run applications other than the ones you specify, they will get an error message that they do not have sufficient access privileges to run the application.
Even more drastic than setting limits is setting Simple Finder, which gives the user a stripped down interface. They get an unconfigurable dock with aliases to their applications, their documents, and the Shared folder. You can further restrict the applications that appear in their applications folder.
In Simple Finder, the Applications folder simply contains aliases to the applications you have allowed them to run, with a pages interface instead of a scrollbar. This takes the place of the old At Ease Finder replacement from OS 9.
Also in the Accounts pane of System Preferences is the Login Options pane, which allows you to configure what the login window looks like, or indeed if any appears at all. By default when you first install Mac OS X, you configure the first administrative account during installation and the computer is set to auto-login as that user. If you have more than one user and want to see the login window, go to Login Options and deselect "Automatically log in as". You can also set the login window to display just username and password entry field, rather than a list of users with little pictures next to them.
The Login Options pane is also where you turn on fast user switching. Mac OS X 10.3 allows you to have more than one person logged in at one time. Mac OS X 10.2 allowed this in the sense that you could log in on the command line and switch users, or log in remotely via SSH while another user was logged in. But Mac OS X 10.3 allows multiple users to be running graphical applications simultaneously. Windows XP also has a similar feature.
Once you've turned on fast user switching in the Login Options pane of Accounts, a menu appears in the right-hand area of the main menu bar. The menu displays your username, and drops down to show a list of all users on this machine (that you've created in Accounts).
Selecting another user from the fast use switching menu prompts you for their password and then logs in as that user, while leaving your own applications running. Or you can go back to the login window and log in as any user. Users that are already logged in will show as "already logged in" in the login window.
If a user is already logged in, you will not be able to edit them in the Accounts pane of System Preferences. You will need to get that user to log out (or become root and kill their Window Manager process) in order to make changes to their account.