Real author:
Gep
A channel build on the values of two moving averages of High and Low, drawn as a cloud.
The indicator uses SmoothAlgorithms.mqh library classes (must be copied to the terminal_data_folder\MQL5\Include). The use of the classes was thoroughly described in the article "Averaging Price Series for Intermediate Calculations Without Using Additional Buffers".
Originally this indicator has been written in MQL4 and was first published in the Code Base on 18.10.2007.

Figure 1. The XChannel indicator