It is a pity that the panel tech behind the OLPC appears to have sunk without a whisper(also a pity that I cannot for the life of me find mine, I have no idea what happened to it).
E-ink has gotten pretty good for acceptably fast ‘page turning’ in ebook readers and similar applications; but if you want to simulate writing you need to shave off every millisecond you can, and probably a few you can’t, which makes electrophoretic displays a poor choice.
The panel in the OLPC had the refresh rate of an ordinary LCD, so substantially better than E-ink, and was extremely sharp and worked without a backlight(in transreflective B/W). The backlit color mode was pretty mediocre; but optional, and adequate in a pinch.
To the best of my knowledge, with those gone, B/W LCDs are pretty much limited to the relatively small(like the ones used in ‘pebble’ watches), assorted segment-based ones of little general purpose use, and extremely pricey(though rather nice) radiology gear for people who take their greyscales seriously.
It’s a pity. E-ink is stubbornly high latency, though it has gotten better at handling changes to just part of the image without having to redraw the whole thing, and obnoxious panel driver requirements(much higher voltages than LCDs). Conventional LCDs have improved; but having your backlight fight the sun will never not suck; and they just don’t seem to make large, bitmapped, transreflective LCDs.
