BitcoinDark is a fork of Bitcoin with a poorly defined purpose and use case. BitcoinDark is based on the InstantDEX protocol, a decentralized exchange for BitcoinDark and other cryptocurrencies supported by the project. The platform is also supposed to include a Pegged Asset Exchange (PAX) to allow users to buy and sell pegged assets – including fiat currencies, commodities, ETFs, and stocks.
BitcoinDark is a Proof-of-Stake (PoS) currency that has gained a significant market cap, but the project has failed to show how its vision will be implemented or how it will add value compared to other blockchain projects.

Sphere is a smart contract platform and peer-to-peer payment network. The network has a hybrid PoW and PoS consensus mechanism and is powered by the native SPHR token, which can be swapped for an ERC20 token over the Ubiq smart contract platform.

Bitcoin Diamond is a hardfork of Bitcoin that was created in 2017. Although the network's code preserves much of Bitcoin's original features, it aims to improve transaction speeds by implementing the Lightning network and increasing the storage capabilities of each block. The Lightning Network is a second layer payment protocol that works on the Bitcoin blockchain and is designed to place a large portion of the transaction data outside of the blockchain.