Kaspa

Kaspa is a PoW-based ledger organized in a DAG (Directed Acyclic Graph) of blocks - a blockDAG.

Every second a new block is added to the block DAG, and many blocks are created in parallel. Unlike blockchains, blocks are not isolated. Kaspa merges all blocks into one blockDAG by allowing them to reference multiple parent blocks.

Instead of deciding which conflicting blocks to discard, the consensus protocol that manages blockDAG (called PHANTOM) orders the blocks created in parallel. PHANTOM is a generalization of Bitcoin's Nakamoto consensus.