Who: Alex Gluchowski, who founded Matter Labs ()
What: zkSync is built using Matter Labs’ zkRollup technology
Where: Stichting ZK Sync, Netherlands Foundation, Amsterdam, NL / head office is in Berlin
When: In 2019, Matter Labs announced a USD 2 million Series Seed financing round led by Placeholder and joined by 1kx, Dekrypt, Hashed, and Dragonfly Capital Partners.
Why: To create Ethereum's most advanced ZK rollup.
How: zkPorter account tx data will be sent to Guardians instead of ETH node calldata (only merkle roots instead)
Strengths: security properties of L1, Withdrawals to L1 in under 15 minutes. and EVM compatible rollups!
Weaknesses: issues: sucidal attempt of 2/3rd of guardians would be possible (unlikely) --> every user can select security level (%) for a specific price
Traction: Gitcoin grants since end of 2020
Future Plans: zkPorter (basically a mix of zkRollups and validium)
zkSync official website: https://zksync.io/
code is open source: https://github.com/matter-labs