Hop is a protocol for sending tokens across rollups and their shared layer-1 network in a quick and trustless manner.
Rollups have the potential to scale the Ethereum network, but each rollup creates a siloed environment for its applications. Moving assets between rollups and the layer-1 network is slow and expensive, diminishing the savings users gain by using the rollup.
The Hop protocol allows assets to be moved directly from rollup to rollup, providing cost savings and enabling cross-rollup composability of applications.
Read more: https://hop.exchange/whitepaper.pdf