What are the possible varieties of E-Tech weapons?

E-Tech guns are quite rare and I've only seen one E-Tech gun of certain types, so I'm not even sure, after >100 hours play, I've seen all of the varieties (much less understand how they all work, I rarely use them).

What are the varieties of E-Tech guns and what's special about each? For instance I know the Snipers are Railguns and the Pistols can fire bouncing or homing shots.