✓Auxiliary proof of work (AuxPoW) ✓Conserves computational power ✓24 second block time
Viacoin (VIA) is an open source cryptocurrency created in 2014, with its underlying technology derived from the Bitcoin protocol. Unlike Bitcoin however, Viacoin is able to offer transactions up to 25x faster due to having a 24 second block time, and can handle 175 transactions per second without scaling through Segwit or Lightning Network.
Viacoin also features a functionality called Scrypt Merged mining or Auxiliary proof of work (AuxPoW), which allows it to be mined at the same time as other cryptocurrencies, conserving computational power.