Most LCD's have a high-level embedded controller, and most follow the same origianal Hitachi pattern. PBP provides for this nicely.

7 segment displays are basically a bunch of lights. There's a hundred different ways you can connect them up. You can have common anode, or common cathode, with one limiting Resistor, or with seven. Driven or undriven. Time multiplexed or constant. etc etc.

It is assumed by manufacturers that most people can connect up a bunch of LED's and make them work in one way or another (LED example at the start of the PBP manual just expanded up seven times is a good start) - folks that can't (or don't want to sit down with a protoboard and play) should really consider a different hobby.