Slightly more transparent label backgrounds and adjusted the radius values to place them within the pie.
Semi-transparent, black-colored label background.
Semi-transparent, black-colored label background placed at pie edge.
Added a semi-transparent background to the labels and a custom labelFormatter function.
Labels can be hidden if the slice is less than a given percentage of the pie (10% in this case).
The radius can also be set to a specific size (even larger than the container itself).
The pie can be tilted at an angle.
A donut hole can be added.
The pie can be made interactive with hover and click events.