Stealth aims to become the leading privacy-focused cryptocurrency. 
 
Stealth provides an end-to-end privacy solution by leveraging a mix of features including integrated TOR network and stealth addresses. Stealth intends to offer zkSNARK-based private transactions. StealthsQuantum Proof-of-Stake (qPoS) signing algorithm aims to set a new standard in the blockchain industry. With the goal of true decentralization, qPoS relies on economic incentives to drive performance. With 5-second blocks, qPoS aims to offer a fast, feeless, private, and scalable blockchain. Using XST, (Stealth’s native currency), transaction validators purchase their rights to process transactions and collect rewards for doing so. These rights are tokenized as transferrable, non-fungible assets called “StealthNodes”, each of which is given slots in a schedule of block validation. This scheduling is intended to make Stealth efficient.

Stealth R&D LLC is the development company behind the Stealth blockchain.  Headquartered in Delaware, Stealth maintains offices in the U.S., Switzerland and Costa Rica.

Stealth

Peercoin, also known as PPC or Peer-to-Peer Coin, was created by Sunny King and his team and launched in August 2012. It is the first blockchain to implement Proof-of-Stake consensus.

The primary inspiration behind the creation of Peercoin was to address a number of perceived shortcomings of Bitcoin, including energy efficiency, security and sustainability, decentralization and long-term viability.

Essentially it was designed as an enhanced replacement for Bitcoin. As such, it was originally forked from Bitcoin and uses the same UTXO style blockchain. However, Peercoin's code was modified to introduce Proof-of-Stake as its primary consensus protocol. The next section explains how this makes for a better blockchain.

Given that Peercoin uses most of the same code, it can easily port new features from Bitcoin and utilize any of the supporting infrastructure, including tech advancements like Taproot or Lightning Network. Peercoin is the only Proof-of-Stake blockchain that uses modern Bitcoin code, making it the perfect drop-in replacement.

Peercoin also has a dedicated community, is actively developed, fairly distributed, has low barriers of participation, can do everything that Bitcoin does, minus the 13 TWh of energy usage, and it's not a scam.

Peercoin

Validity

Ycash

WaykiChain

Graviocoin

GameCredits

TenX

Ruff

Aurora

High Performance Blockchain is the first permissionless public blockchain to innovate with hardware acceleration and provably random numbers:

acceleration delivers fast, ultra low-fee, on-chain transactions

provably random numbers support 100% fairness

HPB (the coin) is used to pay transaction gas fees and to reward node operators.

Hyperblox

SmartCash

Vertcoin

Tachyon Protocol

Library Credit (LBRY) is a platform that seeks to simplify the way digital content is distributed and accessed by both consumers and producers.

Library Credit uses a decentralized model to be fair, free, and open to all the involved parties.

More specifically, the platform functions as a distributed network built on top of a protocol that makes it easy for publishers to charge a fee to content consumers without censorship or the need for a middleman.

The project was launched towards the end of 2018 and is now serving an active community.

LBRY Credits

QuadrantProtocol

PIVX

HyperCash

Kleros (PNK) is a decentralized dispute resolution project that launched in July 2018. It is an open-source online dispute resolution protocol that uses blockchain and crowdsourcing to adjudicate disputes fairly.

Kleros offers a middleman service for decentralized applications (DApps) and their users. If the service provided by the application does not create a dispute, Kleros acts as a trustless third-party service for payment.

When a dispute does occur, however, each party can apply for arbitration through the Kleros arbitrators that are selected from the owners of PNK tokens. PNK is an Ethereum-based ERC-20 utility token with a fixed supply.

At this point, the jurors can make a decision that will favor either party. The arbitration fees are distributed to all arbitrators in the form of ETH; jurors who have issued a minority decision lose part of their PNK tokens for the benefit of the majority of jurors. This decision can be appealed, at a cost. The stated mission of Kleros is to offer easier access to justice and improve individual freedom.

Kleros charges a cost that is payable in ETH and is provided by the parties to the dispute or drawn from the funds previously locked in escrow.