The code was prepared back in 2005. Unlike the original, the smoothing ratio here is raised to power. The power value is set by the G external variable (the default value is 2, like in the original). Several people challenged the authorship of this value, though it is not of much significance here.
The main advantage of wellx version is the color dots identifying a trend.
Kaufman's AMA from wellx
Translated from Russian by MetaQuotes Software Corp.
Original code: https://www.mql5.com/ru/code/7378
The Acceleration/Deceleration Indicator (AC) measures acceleration and deceleration of the current driving force.Average Directional Movement Index (ADX)
The Average Directional Movement Index Indicator (ADX) helps to determine if there is a price trend.