What is a private Ethereum chain? I thought Ethereum was based on the mainnet - how can it be gasless?
Ethereum makes it possible to deploy private instances of their blockchain technology, as described at this link. It may also be helpful to read through this brief description of public vs. private chains on Kaleido. Users can experience the same benefits of immutability, security, etc. of main-net while maintaining the ability to provision access as they see fit. Kaleido’s private Ethereum networks are gasless because they do not operate on main-net’s proof of work consensus algorithm; instead, they use any of Proof of Authority (PoA), Istanbul BFT (Byzantine Fault Tolerant) or Raft which rotates the miners of each new block between member nodes in the network.