SixtyGig_Alpha_64x_MC16.zip is a release file of the Minecraft resource pack SixtyGig Resource Pack (Build 1-14-2013), made for Minecraft 1.6.4. It was published on October 13, 2013 and is 26.2 MB in size. For the full description, screenshots and every other version, visit the SixtyGig Resource Pack (Build 1-14-2013) resource pack page.
How to install: Put the .zip into .minecraft/resourcepacks (do not extract it) and enable it under Options → Resource Packs.
