Third party software

[Packetdancer]

Just as addon isn't Windows a 3party software as it was not made by SQUER ?
So we need some clearance from SQUER

I mean, this is getting a little ridiculous.

But treating the question seriously...? No, it doesn't count as third-party software.

In the sense it's used in the ToS, third party software almost certainly refers specifically to software which either alters the game process from the intended state (mods, in-game overlays, etc.), alters the game data from the intended state (mods that directly affect the game assets on disk), or extracts information not accessible by any other means.

Moreover -- and this is the key point -- any software the game cannot function without is not unauthorized third-party software, but rather part of the game's base operating requirements.

Windows, in contrast, is the host platform on which the software is designed to run; the Windows version of the game cannot function at all without Windows. (Or some sort of reasonably complete Windows-esque API translation layer, a'la WINE, Proton, Crossover and such.)