I know that the login window on OS X can be customized -- you can change the background image, replace the Apple logo, add text and set the size, hide users, and set up login/logout hooks, and, through workgroup manager, set the window to show two text entry fields or a list of usernames, and more.
Is it possible to replace the login window?
Scenario 1: At an elementary school, we would like students in grades 1, 2, and 3 to be able to log in easily. (Teachers tell us that a lot of time is wasted getting students logged in). When you set up a list with names of all the people you'd like to be able to log in to a given computer, you get a huge list. I wish the students could choose their grade (or group) first, and then have a shorter list. Also, you can have tiny icons of people's faces beside the name, but a cover-flow like chooser, where they could look for their face and click on it, would be more useful.
Scenario 2: We would like to have a "student" account for laptop machines, with no password. You log in and are then presented with a utility that asks you to authenticate and mount your home folder (with instructions to save things there as the account will be deleted when you log out.) With a custom login screen, the two steps could be done in one -- you see a login window, choose yourself, and log in. You are logged in as "student" and your home folder is mounted, but it looks like one step.
If it is possible to replace the login window, does anyone know of any replacements or starting points for making one?
Addendum: I have posted a corresponding question on stackoverflow.