GAS is the token that is used to pay for transaction fees on the NEO network. The NEO platform uses two different tokens; GAS are used to fuel the network and give holders the right to use the NEO blockchain. Similar to Ether on the Ethereum network. Although it's possible to buy GAS on some exchanges, NEO token holders automatically generate GAS as the blockchain increases in size. 8 GAS are distributed for every 100 million NEO in circulation.

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ICON (ICX) is unique compared to most other digital currrencies. ICON's primary objective is to establish a unifying system to integrate an unlimited numbers of blockchains. This would allow numerous blockchains to work together and incorporate aspects of all of them. ICON is powered by a unique system called loopchain, that can adopt different features, rules, and consensus systems. The loopchain has different circles, with nodes that connect it. There are community nodes and individual nodes that are all connected to the ICON Republic, which is the entire ecosystem. These nodes can connect in countless ways and results in unlimited applications. The network has an innovative consensus mechanism called Delegated Proof-of-Contribution (DPoC).

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.