This package implements Mac-native "sheet" windows for Tk. "Sheet" windows are dialogs or toplevel windows that slide down from the top of a Mac toplevel window, and then slide back up when they are dismissed. Tk on the Mac has long supported the "sheet" effect for system dialogs, such as tk_messageBox, when a "-parent" option is passed to the call. The macsheet package adds the ability to create customized dialogs or windows with a similar effect.
Macsheet is developed by Kevin Walzer and is available from http://opensource.codebykevin.com/native.html#macsheet