What is AL?

Aether legacy is a port of the Aether for beta 1.7.3 (The original mod.)
It has much less content than Aether 2, but both mods can be used at the same time, and Aether Legacy (As of the creation of this blog) has all 3 dungeons, while Aether 2 is not yet complete, and has none.
Download link: https://www.curseforge.com/minecraft/mc-mods/the-aether