GDI and GDI+
GDI+ is the next step in the evolution of the Microsoft Graphics Device Interface (GDI).
When referring to GDI, spell out the acronym on first mention in a topic: Graphics Device Interface (GDI).
When referring to GDI+, do not spell out the acronym. Also, never use GDIPlus. It is acceptable to use plus as part of a file name, such as Gdiplus.lib.
Correct
GDI+ is the next step in the evolution of the Microsoft Graphics Device Interface.
Many differences exist between GDI and GDI+.
Incorrect
GDIPlus is really cool.
GDI+ is the next step in the evolution of the Microsoft graphics device interface.
The new Graphics Device Interface Plus (GDI+) is great.
The new Graphics Device Interface + (GDI+) is great.