Optimism is an optimistic Ethereum rollup DAO. There's no whitepaper, so it's quite hard to understand what makes them special but there's a blog post that gives you a good idea.
So basically it's an Ethereum rollup that apps pay to use. The revenues are put in a pot and awarded democratically and retroactively to projects that support the system. They call it "retroactive public goods funding". The idea was first developed by Vitalik Buterin. In the beginning phases when there's no protocol revenues yet, the team makes funding decisions and the money comes from 20% of the sold tokens.
So it seems this project is both a rollup and an experiment in governance. Not mind blowing, but still interesting to follow, especially considering how many apps they have running on it. Show Less