## Tcl8.6.15/Tk8.6.15 Documentation > Tk C API, version 8.6.15 > MainLoop

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### NAME

Tk_MainLoop — loop for events until all windows are deleted

### SYNOPSIS

#include <tk.h>
Tk_MainLoop()

### DESCRIPTION

Tk_MainLoop is a procedure that loops repeatedly calling Tcl_DoOneEvent. It returns only when there are no applications left in this process (i.e. no main windows exist anymore). Most windowing applications will call Tk_MainLoop after initialization; the main execution of the application will consist entirely of callbacks invoked via Tcl_DoOneEvent.

### KEYWORDS

application, event, main loop
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