Those are made to drive LCD glass directly. You can buy LCD displays without a controller very cheaply (for instance). They have to be driven in a very precise way or they won't work and can actually be damaged (I think). MCUs with LCD control do that without you having to do all the work yourself.
I have a couple displays I've been meaning to play with. There's one in this picture: **broken link removed**
Was going to do all the timing and AC output myself. Since then I bought a PIC 16F917 that has LCD capability, but still haven't got around to doing it.
Also, have not got around to hooking up the bare glass displays. After seeing one of Blueroom's project's, was going to hookup to an idle 16f917 debug board. This 4 digit Lumex model does static or 1/2 bias, so seemed do-able with the 16f917 in the 1/2 bias mode. Varitronix is another major manufacturer.