RSK is an open source smart contract platform that is secured by the Bitcoin network. RSK is designed to add value and increase the functionality of the Bitcoin ecosystem by providing smart contracts that are compatible with the network's code and can be written in Solidity. RSK smart contracts are powered by the SmartBitcoin (RBTC) which is linked to Bitcoin. (1 RBTC=1 BTC)
RSK developed the RIF Token which is intended to enable users to access a range of DApps within their ecosystem. In September 2019, RSK purchased the Spanish social media platform Taringa with the goal of using the RIF token as an incentive to encourage users to share content.

The Aztec Protocol is an efficient zero-knowledge privacy protocol designed to enable private transactions on the Ethereum blocckhain. Their zero-knowledge proofs enable private transactions that can facilitate a variety of inter-operable financial applications on Ethereum. Aztec is a ConsenSys portfolio company.

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Emercoin is a blockchain-based development platform. It has developed a range of easy-to-use dSDKs (Decentralized Software Development Kits) that can be used to more easily build DApps. This set of software development tools allow the creation of blockchain-based software and services.
Emercoin's dSDKs have been implemented in several innovative DApps and provide developers with solutions for a variety of functionalities. Some of the dSDK's that Emercoin offers are specifically geared for decentralized DNS, SSH, SSL, and DPO solutions.
Emercoin has a hybrid consensus mechanism that combines elements of Proof-of-Stake (PoS) with a Proof-of-Work (PoW) algorithm that is merge-mined with Bitcoin. The network is powered by the EMC coin.