Unobtanium is a Proof-of-Work (PoW) cryptocurrency that uses the SHA-256 hashing algorithm. It was designed to serve as a commodity and store of wealth that would be less vulnerable to price fluctuations. The coin's supply is limited to counter inflation, and UNO coins were distributed in a manner that would discourage centralization. UNO can be merge-mined with Bitcoin.

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.

BurstCoin is a cryptocurrency with a Proof-of-Capacity (PoC) consensus algorithm. Unlike most other cryptocurrencies, Burst's architecture uses a Tangle (similar to IOTA) instead of relying on a blockchain. It also utilizes ring signatures and other features, in what is called the Dymaxion. The Dymaxion implements layers of tangle-based lightning networks on top of the Burst blockchain. Each of these payment channels is opened in the form of a standalone colored tangle. Burst is also developing atomic cross-chain transactions (ACCT), that will allow for full decentralized trading between two cryptocurrencies.