The Guppy Multiple Moving Average (GMMA), using two groups of EMA lines to help visually identify the trend and trading opportunities:
The green lines are groups of shorter period EMA lines, and the red lines are groups of longer period EMA lines. When the stock is on a clear uptrend (or downtrend), these lines will be aligned in order and go in parallel. When the trend changes or the stock price consolidates, these lines will be merged or crossed.
It looks nice. However, GMMA itself does not give extra information more than a group of EMA lines. It is also not useful for setting up automatic trading rules. It is only a nice visual tool to help making trading decisions. e.g. jump on a strong stock when the GMMA lines merged at price consolidation, ride on a stock when GMMA lines aligned and goes parallel.