Ravencoin is a blockchain created by the owner of Overstock.com. It is a use case specific blockchain for the declaration of ownership of digital assets. Ravecoin is a fork of Bitcoin, and was originally funded by Medici Ventures, a blockchain investment fund owned by Overstock.com.
Ravencoin's name is inspired by the use of Ravens in sending messages, and its blockchain is designed to carry statements of truth about who owns what asset. The developers created a new consensus algorithm called x16r to solve the problems of centralized ASIC mining. The algorithm is unique in that it consists of 16 different hashing algorithms whose order are randomly changed.

Ripple is a real-time settlement and remittance network that is designed for the banking industry. Its settlement infrastructure technology has been adopted by a growing list of financial institutions looking to leverage the benefits of distributed ledgers. Ripple's real-time settlement network connects banks and enables cross border settlements and transactions in real-time. The current settlement infrastructure requires many intermediaries, and performing transactions take time and cost money. Ripple provides the underlying infrastructure for banks, and enables these transactions to be executed directly at almost no cost.

Dogecoin is a cryptocurrency with a focus on fun, generosity, and community. It is unlike many other blockchain projects in that it does not aim to solve any ambitious problems. Dogecoin was originally created as a meme coin and has gained a large following that use the coin (DOGE) as an internet tipping and fundraising system.
Although Dogecoin was first created as somewhat of a joke, it has a passionate community that has used the platform for a variety of purposes. The project has gained widespread publicity and DOGE is traded on many exchanges.

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