Some of the most interesting conversations I had at Fortune Brainstorm Tech last week dealt with "Web 3.0" and the concept of open, distributed systems—typically based on blockchain concepts—as a potential replacement for today's Internet, which is dominated by a few very large technology firms.

On stage, Joseph Lubin, one of the founders of Ethereum and CEO of ConsenSys, which develops tools and applications for Ethereum, explained that Bitcoin invented the next generation decentralized database, crypto economics, and token design (i.e., blockchain) which he called "a maximally decentralized trust system." By 2012, he said, many people thought they should be using that database structure for everything, which led to the creation of Ethereum, another blockchain-based system, with a goal of creating what they called "the world computer."

Since then other players have started building tools and infrastructure in different vertical markets. He talked about how ConsenSys is trying not only to build major services, but also build a new trust foundation and settlement layer—a new kind of financial plumbing that can issue billions of dollars worth of digital assets.

Dfinity founder Dominic Williams explained his company's goal of building "The Internet Computer," which he said would run " secure software with a range of superpowers." This, he said, is intended as a complete replacement for the $3.6 trillion IT stack and addresses the difficulty of creating secure IT infrastructure.

This of course, is a major undertaking, and on stage and in conversations with him, he explained that he thought the increasing "monopolization" of the internet is causing a major problem for entrepreneurs and innovation. He cited such things as Zynga building its business on top of Facebook and then Facebook changing the rules; or RelateIQ using various LinkedIn APIs that then were changed, leading to the company being sold to Salesforce.

Williams said that 18 of the last 22 tech IPOs mentioned platform risks as existential threats, and said that if you are building on APIs on top of big tech, "you're building on sand." Instead, he said, Dfinity is building a platform for the creation of open Internet services—essentially an open source project—that would be managed by an independent governance system. One you open up an API, the governance system would guarantee that such APIs would never be revoked.

He talked about building services on top of this system that would work as open versions of WhatsApp, LinkedIn, and Salesforce.

Lubin as well talked up the ability to build on open protocol stack and talked about how "Web 3.0" will involve lots of decentralized open platforms, such as ConsenSys and Dfinity. with massively decentralized governance. This, he said, would let lots of different actors perform their roles while still pursuing their own uses

He noted that Ethereum—while still being smaller than Bitcoin—has created by far the largest blockchain ecosystem in terms of the number of developers. He said, that during the "crypto winter," while some speculators have fled the platform, the entrepreneurs and developer have stayed because they "don't want to go back to web 2.0 architectures." He talked about how Ethereum has already gotten faster, and how Ethereum 2, due out early next year, will offer even more scale.

Both talked about the need for governance, with Lubin talking about the various layers of governance involved in the Ethereum project and Williams discussing "automated governance" as a key feature of the "Internet computer." Williams said such as system is capable of neutralizing "bad actors," while saying there has been a debate whether that's a good thing of a bad thing.

Lubin explained that Ethereum assumed that vast majority of transactions would be between "identified actors" with systems for identity and reputation to comply with regulations such as "know your customer" (KYC). But he acknowledged that there was a "deep philosophical issue" whether the base trust layer should be permission-less or should be able to be controlled by government.

I'm not totally convinced that such completely decentralized systems really can gain the kind of economic scale that the backers of these plans envision. I remember hearing much the same vision about the first generation of the Internet and how it would remove the need to intermediaries—something that just didn't work in practice. But it is a fascinating vision and one that seems worthy of a lot more attention than it has been getting.