GDI+ is a new graphics subsystem for Windows and provides a new set of graphics APIs for rendering 2D graphics, images, and text. GDI+ is the only API for drawing in the .NET Framework, but in Delphi it is a complement to the current GDI to provide more advanced rendering capabilities.
Here's what you get with GDI+: antialiased 2D drawing, alpha channel support, universal transformations and floating point coordinates, gradient brushes, cardinal splines, scalable regions, and a new programming model.
The GDI+ feature can be easily redistributed. GDI+ is standard on Windows XP. For Windows 98, Windows Me, Windows NT® 4.0, and Windows 2000, you can simply copy GdiPlus.DLL into your app's directory.
GDI+ uses a different programming model from GDI. Instead of selecting brushes and pens into a device context, in GDI+ you pass the pen or brush into every drawing command. Graphics elements are no longer drawn with both the pen and brush together; they are outlined and filled using separate functions (such as DrawRectangle and FillRectangle).