Ethereum

A truly private l2 that's been under construction for almost a decade now

Launching with stage 2 decentralization on day 1 with full onchain (opt in) privacy

In other words, a zk rollup that actually uses the zk property of zero knowledge and not just succintness

So are all transactions private or just anonymous? Where can I read about it?

Private, not just anon - actually confidential and shielded 

You can do a swap on a dex and nobody gets to see who, what token, and what amount

Read their docs at aztec.network

Woah

Does it have native AA like the other zk chains?