Namecoin is a blockchain-based DNS that allows users to register domain names with a ".bit" domain. Namecoin was the first fork of the Bitcoin protocol and it aims to remove centralized control over domain registration. It was the first cryptocurrency to use Auxiliary Proof of Work (AuxPoW) as a consensus mechanism,
where a child blockchain is dependent on the Proof-of-Work consensus of the parent blockchain. This allows for Namecoin and Bitcoin to be mined simultaneously, and when a new block is created on Bitcoin, it will also be added to the Namecoin blockchain.
Namecoin is a very important project that represents one of the best use cases of blockchain technology in protecting free speech and resisting censorship on the internet. It is powered by the NMC coin. The decentralized DNS provides more security from hackers and government intervention.

TrueChain is developing a secure and scalable blockchain platform with a strong developer community. TrueChain hopes to improve upon current platforms with a hybrid consensus protocol called Minerva. This hybrid model will combine a consensus mechanism based on Practical Byzantine Fault Tolerance (pBFT) with a FruitChain-based Proof-of-Work protocol. Fruitchain is designed to minimize the incentives of mining pools by decreasing the variance of mining rewards; making the network more decentralized.
TrueChain's architecture also hopes to improve transaction times and reduce fees, by including a sharding mechanism that is locked to Gas fees. The first use cases for their platform will be digital advertising solutions.
The company is backed by several large Chinese blockchain companies, including ZB.com; one of the largest cryptocurrency exchanges. digital advertising industry

Skycoin began as an ambitious infrastructure project aimed at replacing the Proof-of-Work (PoW) and Proof-of-Stake (PoS) consensus algorithms that dominate current blockchain platforms. It has since evolved into a project focused on creating a decentralized mesh-Internet and a platform for other blockchain-based projects. Skycoin is developing an ecosystem with a variety of goals, including: the elimination of mining rewards, development of energy-efficient custom hardware, advancing security and privacy, and achieving transaction speeds that rival current digital payment systems. The ecosystem consists of the native SKY coin, Skywire (decentralized mesh-Internet), Skyminer (hardware and access point for Skywire), Skyledger (decentralized open blockchain network), and a suite of DApps. The consensus algorithm is called Obelisk. The network's nodes agree based on a Web-of-Trust consensus. The ability to influence transaction verification is distributed over the network creating a web of trust. To eliminate mining completely each node on the network connects to a list of nodes that it sees as trustworthy.