This paper aims to provide an overview of how Blockchain and other distributed ledgers, specifically their underlying consensus mechanisms, have evolved over time. The consensus mechanism provides the technical infrastructure layer for blockchains. This makes it one of the most critical components when assessing real-world use cases. It is based on KPMG research as well as the results of interviews with more than 20 creators and corporate users of blockchains and other distributed ledgers. The paper will review how various distributed ledger consensus mechanisms continue to evolve and are currently being tested and, in some cases, implemented.