Grin is a lightweight cryptocurrency that implements the Mimblewimble protocol, striving to offer a unique balance of privacy and scalability. Unlike many other cryptocurrencies, Grin has no addresses, no amounts, and no need to store data of spent outputs. It is fully open-source and community-driven, with no single entity behind it. Grin's development is funded by donations and contributed to voluntarily by developers around the world. The coin distribution process is designed to be as fair as possible, with a linear emission of 1 GRIN per second, forever. This design strives to ensure the long-term security of the chain and a fair process of coin distribution to all participants.

Grin operates on the Mimblewimble protocol, which leverages cryptography to allow past transaction data to be removed without compromising security. This helps prevent the blockchain from becoming overwhelmed with data. Grin's block time is one minute, with a coinbase reward of 60 grins, creating one unit per second indefinitely. This linear emission results in a constant increase in supply but a decreasing rate of inflation, making the emission disinflationary. Transactions can be trivially aggregated, and to hide the origin of a newly created transaction, it gets relayed among a subset of peers before it is widely broadcasted.

Grin strives to provide a privacy-preserving digital currency that can be used by anyone, anywhere, without censorship or restrictions. It is designed for the decades to come, not just for tomorrow. The absence of addresses and amounts in Grin's design allows for a high level of privacy, as transactions can be easily aggregated and origins of transactions are hidden. This could make Grin a choice for individuals and businesses that prioritize privacy and security in their financial transactions. Furthermore, Grin's design strives to ensure long-term security and fairness, which could make it a choice for those who value these aspects in a digital currency.

Grin's history began in August 2016 when an anonymous person using the nickname 'majorplayer' dropped a link to a document titled 'Mimblewimble' in a Bitcoin research IRC channel. The document was authored under the pseudonym Tom Elvis Jedusor. Several developers took an interest in the document, including Andrew Poelstra, who later published a paper adding several refinements and a detailed technical description of the original whitepaper. In October 2016, a developer under the pseudonym Ignotus Peverell began work on developing an implementation of the protocol. This project, which was joined by others, eventually became known as Grin. Grin launched on January 15th, 2019.