PopupBox components can be used with Delphi 2, 3, 4, 5 and C++Builder 1 & 3. They look like a ComboBox by default, but you can change look and behavior. You can for instance determine:

• when the list should drop down
• what happens if you select a list item
• different size for edit box and list box
• different alignment, color and font for edit box and list box
• if / when a Popup-Button appears
• many more settings...

If you don't like the way, PopupBox-list handles Return-Key / MouseClicks, you can simply change this behavior in Delphi's Object inspector. Optional the next window control can be focused automatically after a list item was selected (see properties List.DoOnClick and List.DoOnReturnKey). The list can drop down not only at run-time, but also at design-time. You can see how the list will appear before you compile your program.