The stackengine package provides a versatile way to vertically stack
objects in a variety of customizable ways.  A number of useful macros
are provided, all of which make use of the stackengine core.  These
macros allow a wide variety of tasks, including: 

-creating aligned stacks of specified inter-item gap;

-creating aligned stacks of specified inter-item baselinse shift;

-stacking both above and below the baseline; 

-overlaying character glyphs; 

-insetting graphical images atop larger background images; 

-top and bottom lapping; 

-shifting the horizontal axis of a stack;

-changing the baseline of an object; 

-subfigure stacking and labeling;

This package can be set to process its arguments in either text mode or
in math mode.