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.

• SkinCrafter 1.4.1
  SkinCrafter component lets developers create applications that users can easily skin. With support for Windows Forms (.NET), MS Visual C++, MS Visual Basic, Delphi, and all Win32...

• TWAIN Toolkit for Delphi 2.
  TWAIN made Easy You can now easily implement the TWAIN standard into any Delphi application with the TWAIN Toolkit for Delphi

• DIContainers - Commercial 1.x
  DIContainers are a collection of over 60 container classes for Borland Delphi 4/5/6/7. Four different container structures are available: Hash containers, doulbly-linked Lists, N-ary Trees, and Vector containers.

• DIContainers - Source Code 1.x
  DIContainers are a collection of over 60 container classes for Borland Delphi 4/5/6/7

• Xselerator 2.0.44
  Here are some of the features you can get in Xselerator: Editor
  ---
  * Clear and easy to use IDE;
  * XSL/XSLT element and attribute intuitive (like Intellisense or code insight) drop-downs;
  * Automatic tag completion - in XSL/XSLT tag completion follows model and, optionally, fills element with mandatory attributes; * ...

• AutoCommenter 1.
  AutoCommenter will generate a comment for each function/ procedure/ constructor/ destructor and maintain it when you apply changes to your source