zkSync is a scaling and privacy engine for Ethereum. Its current functionality scope includes low gas transfers of ETH and ERC20 tokens in the Ethereum network.
This document is a description of the supplementary infrastructure of the project.
The majority of the projects are developer infrastructure, targeted at those who contribute to zkSync.
Each of the project has its own README.md, which describes it the best way possible.
The changelog of the infrastructure is avaliable here.