Dawn of the Tiberium Age (DTA) is a stand-alone mod that combines Tiberian Dawn (C&C 95) and Red Alert. While classic mode gets as close to the original game-play and balance as possible, Enhanced mode provides improved game balance and a lot of fun new stuff. DTA features many customization options for Skirmish and multiplayer (where you can play as GDI, Nod, Allies and Soviet on over 100 maps), challenging original singleplayer missions, as well as co-op missions. Since this is a stand-alone mod, you don't require anything but the mod itself to be able to play: the original game is not required.
As explained in the news post, the strength of Harbinger's plasma projectile dissipates over time, allowing its user to choose between a safer range with more trail damage but less single-target damage, or a shorter range for maximum single-target rip-and-tear.
This image shows the damage fall-off at different ranges. A full-HP Medium tank facing the Harbinger at point-blank gets completely destroyed by a single shot, while at maximum range, 3 shots are needed for the same effect.