Is IFP a tax?

Maybe.

IFP is a proposal by ABC to add a dev fund like Zcash.

They want to hire more devs.
They say the success of OF Zcash and Dash and want to replicate it.

Will they?
I don't think so.
It very centralized it just going to ABC. They might do a foundation but still meh.
Another thing it violates the original plan.

It also a soft fork so as long as ABC holds mining power, it activates