Nimbus ETH2.0 Beacon chain + validator
Nimbus is a client implementation for both the consensus layer (eth2) and execution layer (eth1) that strives to be as lightweight as possible in terms of resources used. This allows it to perform well on embedded systems, resource-restricted devices (including Raspberry Pis and mobile devices).
However, resource-restricted hardware is not the only thing Nimbus is good for. Its low resource consumption makes it easy to run Nimbus together with other workloads on your server (this is especially valuable for stakers looking to lower the cost of their server instances).