Arrival_of_Darkness_64x_v_0.8.0_.zip is a release file of the Minecraft resource pack Arrival of Darkness 64x. It was published on September 29, 2012 and is 6.8 MB in size. For the full description, screenshots and every other version, visit the Arrival of Darkness 64x resource pack page.
How to install: Put the .zip into .minecraft/resourcepacks (do not extract it) and enable it under Options → Resource Packs.