Technically true, but I'm pretty sure the great majority of "e-paper" displays are in practice electrophoretic displays, most of which are made by the company E Ink.
Some 15 to 20 years ago there were a lot of other companies trying to create reflective (= e-paper) screen technology based on principles other than electrophoresis, some with native color or fast pixel response times, but they all closed shop.
The only other major type of e-paper that is still used is simple reflective greyscale LCDs. These are not bi-stable but achieve fast pixel response times. The main disadvantage is that they have significantly worse reflectivity, resulting in rather greyish whites.
Some 15 to 20 years ago there were a lot of other companies trying to create reflective (= e-paper) screen technology based on principles other than electrophoresis, some with native color or fast pixel response times, but they all closed shop.
The only other major type of e-paper that is still used is simple reflective greyscale LCDs. These are not bi-stable but achieve fast pixel response times. The main disadvantage is that they have significantly worse reflectivity, resulting in rather greyish whites.