This page intends to always list the correct version that you should use.
Addons here are a mix of Vanilla 1.12 addons from 2006, newer pserver-era 1.12 addons, and versions of addons updated specifically to work correctly on Turtle. As such, Classic addons (1.13/1.14) DO NOT WORK! If you are coming from Classic, clear your mental slate and be prepared to find a completely new set of addons to accomplish what you want. Turtle WoW is a mod on the 2006 version of the game, using the 1.12 client.