These 5 companies are betting on Ethereum to completely reinvent the back end of the internet

If you ask a room full of blockchain enthusiasts how the technology will affect the internet, the answers range from "a lot" to "more than you can even imagine."

Such responses were easy to elicit at the Ethereal conference in San Francisco on Friday. The gathering is a a day-long event for the founders, engineers, and enthusiastic users of a blockchain protocol called Ethereum.

Blockchain technology - also known as smart contract, or digital ledger technology - is the digital system behind bitcoin and a number of other unrelated applications. The technology isn't yet in widespread use, but many experts and enthusiasts believe it will soon become a pervasive new layer of the internet, underlying everything from payments to legal contracts to users' identities.

Many have pinned their hopes for the future impact of blockchain technologies on Ethereum. The protocol underlies a cryptocurrency called ether, which is bought and sold on many of the same exchanges where bitcoin is traded. But enthusiasts believe its real potential is as a foundation for new tools and services.

Ethereum has some obstacles to overcome before it becomes a world-changer. As of June, the protocol could only handle about 13 transactions per second. That's far shy of what Visa can handle, much less the giant online networks. Facebook, for example, handles about 175,000 requests each second.

Still, people are routing around Ethereum's limitations and are already developing unique and interesting projects using or related to the technology.

Here are five of those projects, as explained by the people behind them:

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