Multipool.us is a multi-coin profit-switching Template:Mining pool that mines Bitcoins and several alternate cryptocurrencies (Altcoins).
Multipool was the first pool to offer a port that switches automatically based on coin profitability (the "Multiport") At first, the pool offered Scrypt coins only, but as it grew in popularity, added a SHA-256 Multiport which currently mines 5 different coins (Bitcoin, Terracoin, Freicoin, PeerCoin, Zetacoin).
Miners are not limited to using the profit-switching port. Miners can connect to any of the individual pools to mine a single coin directly.
Rewards are currently distributed using a proportional system, due to the pool's hopping nature.