NXT ticked me off by being closed source.
NXT has been open source for a long time now.
Nxt never was really closed source for those who wanted to look, the original java files were unobfuscated code and could be decompiled.
The point was they went out of their way to try and hide.
I hope NEM follows a clear transparent path.
They won't. No pure PoS (PoI, whatever) ever did or will be fully open source immediately. It's not possible to do it as with PoW, where the hashrate matters. New PoS coint need, absolutely need some lead time before they are cloned. Without it they would drown in clones.