diff -r 6c2e2de5ab8e Lib/idlelib/searchbase.py
--- a/Lib/idlelib/searchbase.py	Sat Jul 30 23:51:13 2016 -0700
+++ b/Lib/idlelib/searchbase.py	Mon Aug 01 11:28:18 2016 -0700
@@ -1,7 +1,7 @@
 '''Define SearchDialogBase used by Search, Replace, and Grep dialogs.'''
 
-from tkinter import Toplevel, Frame
-from tkinter.ttk import Entry, Label, Button, Checkbutton, Radiobutton
+from tkinter import Toplevel, N, W, E, S
+from tkinter.ttk import Entry, Label, Button, Checkbutton, Radiobutton, Frame
 
 class SearchDialogBase:
     '''Create most of a 3 or 4 row, 3 column search dialog.
@@ -43,6 +43,8 @@
         self.root = root
         self.engine = engine
         self.top = None
+        self.windowingsystem = root.tk.call('tk', 'windowingsystem')
+        
 
     def open(self, text, searchphrase=None):
         "Make dialog visible on top of others and ready to use."
@@ -75,14 +77,19 @@
         top = Toplevel(self.root)
         top.bind("<Return>", self.default_command)
         top.bind("<Escape>", self.close)
+        if self.windowingsystem == 'aqua':
+            top.bind("<KP_Enter>", self.default_command)
+            top.bind("<Command-.>", self.close)
         top.protocol("WM_DELETE_WINDOW", self.close)
         top.wm_title(self.title)
         top.wm_iconname(self.icon)
         self.top = top
+        self.inner = Frame(top, padding=10)
+        self.inner.grid(column=0, row=0, sticky=N+W+E+S)
 
         self.row = 0
-        self.top.grid_columnconfigure(0, pad=2, weight=0)
-        self.top.grid_columnconfigure(1, pad=2, minsize=100, weight=100)
+        self.inner.grid_columnconfigure(0, pad=2, weight=0)
+        self.inner.grid_columnconfigure(1, pad=2, minsize=100, weight=100)
 
         self.create_entries()  # row 0 (and maybe 1), cols 0, 1
         self.create_option_buttons()  # next row, cols 0, 1
@@ -95,9 +102,9 @@
         entry - gridded labeled Entry for text entry.
         label - Label widget, returned for testing.
         '''
-        label = Label(self.top, text=label_text)
+        label = Label(self.inner, text=label_text)
         label.grid(row=self.row, column=0, sticky="nw")
-        entry = Entry(self.top, textvariable=var, exportselection=0)
+        entry = Entry(self.inner, textvariable=var, exportselection=0)
         entry.grid(row=self.row, column=1, sticky="nwe")
         self.row = self.row + 1
         return entry, label
@@ -113,11 +120,11 @@
         label - Label widget, returned for testing.
         '''
         if labeltext:
-            label = Label(self.top, text=labeltext)
-            label.grid(row=self.row, column=0, sticky="nw")
+            label = Label(self.inner, text=labeltext)
+            label.grid(row=self.row, column=0, sticky=W)
         else:
             label = ''
-        frame = Frame(self.top)
+        frame = Frame(self.inner)
         frame.grid(row=self.row, column=1, columnspan=1, sticky="nwe")
         self.row = self.row + 1
         return frame, label
@@ -129,7 +136,7 @@
         A gridded frame from make_frame is filled with a Checkbutton
         for each pair, bound to the var, with the corresponding label.
         '''
-        frame = self.make_frame("Options")[0]
+        frame = self.make_frame("Options:")[0]
         engine = self.engine
         options = [(engine.revar, "Regular expression"),
                    (engine.casevar, "Match case"),
@@ -147,7 +154,7 @@
         Others is a list of value, label pairs.
         A gridded frame from make_frame is filled with radio buttons.
         '''
-        frame = self.make_frame("Direction")[0]
+        frame = self.make_frame("Direction:")[0]
         var = self.engine.backvar
         others = [(1, 'Up'), (0, 'Down')]
         for val, label in others:
@@ -161,16 +168,21 @@
                    text=label, command=command,
                    default=isdef and "active" or "normal")
         cols,rows=self.buttonframe.grid_size()
-        b.grid(pady=1,row=rows,column=0,sticky="ew")
+        if self.windowingsystem == 'win32':
+            b.grid(pady=[0,2], row=rows, column=0, sticky=E+W)
+        else:
+            b.grid(column=cols, row=0, padx=2)
         self.buttonframe.grid(rowspan=rows+1)
         return b
 
     def create_command_buttons(self):
         "Place buttons in vertical command frame gridded on right."
-        f = self.buttonframe = Frame(self.top)
-        f.grid(row=0,column=2,padx=2,pady=2,ipadx=2,ipady=2)
-
-        b = self.make_button("close", self.close)
+        f = self.buttonframe = Frame(self.inner)
+        if self.windowingsystem == 'win32':
+            f.grid(row=0, column=2, padx=[5,0], pady=0)
+        else:
+            f.grid(row=99, column=0, columnspan=2, sticky=E, pady=[10,0])
+        b = self.make_button("Close", self.close)
         b.lower()