Cryptocurrencies are digital currencies that use a digital ledger, or blockchain, to record financial transactions. There are several popular crypto-coins, including the most popular, Bitcoin, plus Litecoin, Ethereum, Ripple, and ZCash, among others. Application Programming Interfaces, or APIs, are used by developers to create crytpocurrency trading and data applications. And if the large number of APIs added to ProgrammableWeb Cryptocurrency category in the past few years proves anything, it is that digital cash is booming. Developers wishing to learn more about this technology should definitely read our comprehensive Developer's Guide To Blockchain and Cryptocurrency, and peruse the Cryptocurrency category for hundreds of APIs and other great resources. To receive updates about Cryptocurrency APIs, click the TRACK THIS CATEGORY button below. And, if you want updates from other ProgrammableWeb categories, be sure to click the track button on those category pages as well.