This is a new gump system to replace the old one. In this new system, gumps are handled in a more object oriented manner, and are no longer dealt with globally. The code is more optimized so the gumps will not take as many cycles to be generated.
It was also setup so the function prototypes are similar to the old one for faster migration times.
Included is a text command, called previewgump.src that shows how a gump can be assembled. It shows various tricks and techniques that can be used to put one together.Also, the long list of graphical constants in the gumps.inc were removed and placed in a config file. See GumpCfgInfo() in gumps_ex.inc for more information.