Decred (DCR) is a decentralized currency with an emphasis on community based governance. Decred is led by several early adopters of Bitcoin and is designed to implement many of the goals of early Bitcoin idealists. Decred is highly focused on community contribution and governance. Users that contribute to the community can receive compensation for their work and anybody can submit a proposal ti make an improvement to the platform.
Decred has a hybrid Proof-of-Activity (PAC) consensus algorithm that combines the mining of Proof-of-Work (PoW) with the stake verifying model of Proof-of-Stake (PoS). It's designed to incentivize the community to participate and to reward both miners and stake verifiers. When DCR is mined, PoW miners receives 60% of the coins, PoS voters receive 30%, and 10% goes towards the development of the Decred platform.

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The Cardano blockchain is a 3rd generation blockchain platform that was designed with a collaborative peer-to-peer review system, It aims to improve upon prior blockchain systems to enable larger and more sustainable uses of the technology.
Cardano was built with a governance model that is based on collaboration. This allows the platform to evolve quickly and adapt to the changing needs of its users. Unlike many other blockchain projects, it also installed a treasury system to fund the ongoing development needs that may arise as it moves forward.
The Cardano blockchain uses a unique proof of stake algorithm called Ouroboros and has a protocol that consists of two layers, a settlement layer and a control layer. The settlement layer is designed to perform accounting functions, while the control layer is tasked with running smart contracts. The platform tries to balance the privacy concerns of users with the requirements of regulators in an effective way.
Cardano uses the Haskell programming language and is fueled by the ADA coin

Apollo is developing an all-in-one cryptocurrency platform, based on the APL coin. Apollo was created as a fork of NXT, and has a very ambitious plan to integrate a variety of services under one platform, with a strong focus on privacy. Apollo's blockchain is called Hermes and has a Proof-of-Stake consensus mechanism. Some of the features that Apollo's marketing materials claim they are working on are: private transactions with IP masking, smart contracts, encrypted messaging, file sharing, a decentralized marketplace, voting system for governance, decentralized data storage, and a wallet with a built in exchange. John McAfee, a notable blockchain enthusiast and antivirus pioneer, joined the project in October 2018.