Mac OS X v10.4, 10.5, 10.6
You may see this dialog such as this in Mac OS X v10.5 and later (a similar dialog appears for Mac OS X 10.4 with a Reopen button instead of Relaunch):
In Mac OS X v10.6 and later, the above dialog will reappear if the application unexpectedly quits again. The below dialog does not appear in Mac OS X v10.6.
Mac OS X v10.4 and 10.5 only
If you click Reopen but the application unexpectedly quits again in Mac OS X v10.4 or 10.5, you will be presented with a similar option to reset and relaunch (reopen), shown below for Mac OS X 10.5.
The "Reset and relaunch" option resets the application's preference settings to a default, then opens the application again. Note: Some applications, such as Mail, may store a lot of information in preference files. You may need to spend some time reconfiguring your application's settings if you click "Reset and relaunch".
Want to send a report?
When an application unexpectedly quits, you have the option to report the issue or reopen the application. If you wish to notify Apple about your application unexpectedly quitting, click Send Report in the dialog. Although you won't be contacted directly about your issue, your contribution helps Apple track issues and improve software.