The most recent advance has been the introduction of Film compensated Super Twisted Nematic (FSTN) displays. It adds a retardation film on the STN display that compensates for the color added by the birefringence effect. This enables a black and white display to be produced and provides for a higher contrast and wider viewing angle.
The FSTN technology comes in a single coloration, Black characters on a White / Gray background. Among the three technologies listed here, it is the most expensive one, but it has better viewing angle and contrast than the STN technology listed above.