Bitcoin is by far the largest blockchain-based currency, although several others exist with slightly different technical features. Differences are often found in the mining process, which can require substantial computing resources. For example, some currencies use less resource-intensive algorithms than Bitcoin. Peercoin's algorithm is designed to become less resource intensive as it develops. They also vary in the rate and mechanism by which new currency is generated and distributed, (therefore, in their inflation policies). Many have a predefined maximum number of coins and, once this cap is reached, no new coins will be generated and miners will profit only from transaction fees. Some currencies use algorithms that are designed to avoid the emergence of 'professional miners' that use specialist mining equipment.
Because transactions cost very little (currently from €0 to €0.10), but provide a permanent, secure record, it is possible to use Bitcoin blockchain for other non-financial purposes. This 'piggybacking' could be used to explore and launch several other non-currency-related applications from voting to patent protection. While this kind of approach prevents the developer from implementing bespoke features that they may have introduced in their own blockchain implementation, it does provide a low-cost, readily accessible and stable infrastructure, making it an excellent 'sandpit' for exploring ideas. Other blockchain-based currencies have been set up with wider applications explicitly in mind. Ethereum is a blockchain implementation set up following Vitalik Buterin's white paper and crowdfunding campaign. It includes a currency (ether, which is described as 'fuel') and also a code that can be used to implement a wide range of non-financial functions (see smart contracts, digital rights management and decentralised autonomous organisations).