Creating gaseous effects.

how would i create gas and smoke in blender? i know about using alpha with an animated texture. Is there a way of doing it in blender? A script?

particles with deflectors/attractors, maybe an invisible tube as deflector, or a lattice. this for the “correct” motion. shading - well halo’s is the only option. details depend on what exactly you need - rocket engine exhaust or rather cigarette smoke