Lotus is an implementation of the Filecoin Distributed Storage Network.
It is written in Go and provides a suite of command-line applications:
lotus): a Filecoin Node: validates network transactions, manages a FIL wallet, can perform storage and retrieval deals.
lotus-miner): a Filecoin miner. See the the respective Lotus Miner section in the Mine documentation.
lotus-worker): a worker that assists miners to perform mining-related tasks. See its respective guide for more information.