Bitcoin continues to lead the pack of cryptocurrencies, in terms of market capitalization, user base and popularity. Nevertheless, virtual currencies such as ethereum and ripple, which are being used more for enterprise solutions, are becoming popular, while some altcoins are being endorsed for superior or advanced features vis-à-vis bitcoins. Going by the current trend, cryptocurrencies are here to stay but how many of them will emerge as leaders amid the growing competition within the space will only be revealed with time.
In 1998, Wei Dai published a description of "b-money", characterized as an anonymous, distributed electronic cash system. Shortly thereafter, Nick Szabo described bit gold. Like bitcoin and other cryptocurrencies that would follow it, bit gold (not to be confused with the later gold-based exchange, BitGold) was described as an electronic currency system which required users to complete a proof of work function with solutions being cryptographically put together and published. A currency system based on a reusable proof of work was later created by Hal Finney who followed the work of Dai and Szabo.