I feel like it is important to point out that Steam does not require games to have any DRM. Not even Steam's DRM. It's entirely up to the game developer and/or publisher. Many games on Steam are already DRM-free where you can just back up the files and play without Steam.
Does this apply to AoE? I never played it much in its hey-day but it would be interesting to get into properly. I have no interest in buying an old game with DRM given the obvious potential for maintenance issues though.
Thank you for pointing that out. I am afraid that AoE is probably not one of them though?
Maybe the old AoE versions will be open-sourced one day, that would be awesome.