what are the biggest /zk projects? think I only know zk-sync and scroll

Linea, Taiko, Hermez/polygon, Starknet, Aztec…  

So many and growing hard to keep count

Blockchain scalability, privacy, and usability

Thats just the tip of the iceberg.  Many more in the zk eco, from zk chips enabling proof acceleration to zk proof markets to zk L1s/L2s to zk bridges, zk oracles, to zk apps and zk dev tools.  Probably at least 50 projects within the zk stack.  And that excludes non-blockchain related zk projects, which are coming