Here are some of my macros.
Some of them take a very long time to render on a large terrain!
Beach generator
Generates a beach based on water height.
It basically flattens the land under the selected height with an option to keep rocks that are steeper than specified.
Takes a long time to render.
Standard version
Curved terrace
Creates terraces that aren’t flat, but curving.
Basic version
Island generator
Creates an island with various options.
Takes a long time to render.
Standard version
Coverage generator
Creates masks like terragen does: height, slope, fuzzyness, coverage…
Standard version
You are free to do whatever you want with it.