Spendcoin is an open-sourced cryptocurrency designed for the Cross Ledger Ecosystem, which includes the Spend App and the Blockchain University. The project is run by the Spend Foundation. Their network is currently powered by the Ethereum-based SPND token. Users receive tokens for performing tasks in the Spen ecosystem.

Aurora is developing a blockchain platform that is based on a hybrid dPoS and BFT consensus mechanism. Aurora aims to improve overall blockchain performance with better transaction speeds and security features. Aurora has a multi-chain architecture and an Intelligent App Isolation system that are designed to allow for better smart contract execution. The network is currently powered by the Ethereum-based AOA token.

Primecoin is a cryptocurrency based on finding prime numbers. Identifying prime numbers plays a central role in cryptography. Primecoin's unique Proof-of-Work (PoW) consensus mechanism is able to increase transaction speeds and improve energy efficiency.
The network searches for special prime number chains known as Cunningham chains and bi-twin chains, which are of interest in mathematical research.