Scrypt is used in many cryptocurrencies as a proof-of-work algorithm. It was first implemented for Tenebrix (released in September 2011) and served as the basis for Litecoin and Dogecoin, which also adopted its scrypt algorithm. The idea behind scrypt is to deliberately make the time–memory trade-off. Thus an attacker could use an implementation that doesn't require many resources (and can therefore be massively parallelized with limited expense) but runs very slowly, or use an implementation that runs more quickly but has very large memory requirements and is therefore more expensive to parallelize.

Coins that can be mined with Scrypt:

Veles[scrypt] Dogecoin Litecoin

Best devices to mine Scrypt