diff -r da852f5250af Lib/idlelib/run.py
--- a/Lib/idlelib/run.py	Tue Jun 11 22:13:17 2013 -0500
+++ b/Lib/idlelib/run.py	Tue Jun 11 22:19:25 2013 -0500
@@ -339,6 +339,10 @@
                 exec(code, self.locals)
             finally:
                 interruptable = False
+        except SystemExit:
+            # Scripts that raise SystemExit should just
+            # return to the interactive prompt
+            pass
         except:
             self.usr_exc_info = sys.exc_info()
             if quitting: