These indicators, from John Ehlers' book "Cybernetic Analysis for Stocks and Futures", are EMA alternatives.
The basic idea behind all these is to try to get smoothing with as little lag as possible. As you can see from the chart, they are much smoother, have better response, and a closer match to market prices.
Basically, all the responsiveness of a faster EMA, with the smoothing of a slower EMA :)