The Wolfram Language allows any front end command to be executed programmatically from within the kernel by sending an appropriate front end token. There are tokens for all standard menu commands—as well as ones not accessible directly with the default front end menu configuration.

FrontEndTokenExecute — execute a menu-like command specified by a front end token

"StackWindows" — arrange windows in an overlapping stack

"TileWindowsWide" — arrange all windows to fit one above another

"TileWindowsTall" — arrange all windows to fit one beside another