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.

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

Kadena is a software development company that builds blockchain-based platforms for a range of businesses. They develop purpose-built blockchain solutions for their clients by using proprietary solutions that are aimed at being both secure and scalable. Kadena offers both private and public blockchain platforms, with smart contracts written in the Pact programming language. They've also developed an innovative proof-of-work architecture called ChainWeb that could have a variety of applications.
Kadena's founders have experience working for the U.S. Securities and Exchange Commission (SEC) and JPMorgan Chase Bank. The company has raised significant funding and is well positioned to be play a big role in developing future blockchain solutions for large financial institutions.