While we’re accustomed to referring to it in the singular—the blockchain—the reality is that blockchains exist in the plural. It’s hard to get a rough count of how many there are, unlike the number of available cryptocurrencies, because there are public, private and consortium blockchains. A blockchain, in essence, is just a data structure. But there are several ways to build that structure.

As a result, different blockchains operate under different protocols, algorithms, and software. And as blockchains proliferate, there’s a growing need to be able to link them together, to get them talking to each other. In other words, exactly what blockchain dev firm HACERA has been working on: a Yellow Pages for blockchain.

Today, HACERA announced the imminent launch of that project, which it’s calling “Unbounded,” with IBM joining on as a founding member.

“Unbounded Registry” Will Catalog Blockchains and Blockchain-Based Businesses

HACERA and IBM’s “Unbounded Registry” aims to be a decentralized way of registering, looking up, joining and transacting across and between different blockchains. Insofar as the registry will act as a catalog of different blockchains and blockchain-based businesses, it will resemble the now-deprecated Yellow Pages phonebook of yore.

But the Unbounded Registry will be much more than just a static list of existing blockchains. Unbounded is built on blockchain technology itself, says Jerry Cuomo, IBM’s VP of Blockchain Technology. “Built to interoperate with all of today’s popular distributed ledger technologies.”

Writing on IBM’s blog, Cuomo said Unbounded represented the “third wave” of innovations designed to make businesses known to the world. First, phone books put businesses on the map in the nineteenth century. Then, the 1990s Domain Name System (DNS) created a unique listing for every business name and address on the internet. And now, blockchain allows consumers and providers of blockchain services to find each other and securely interact.

Unbounded Registry Creates Interoperability Between Popular Blockchains

IBM Creates Blockchain Yellow Pages

IBM and HACERA want the Unbounded Registry to bring blockchains and blockchain-based businesses together. And the key to that is interoperability. Unbounded will be capable of interoperability with major distributed ledger technologies, including The Linux Foundation’s Hyperledger Fabric, Hyperledger Sawtooth, R3 Corda, EEA Quorum and Stellar Network.

Furthermore, new members can apply to join the Unbounded Registry. IBM and HACERA have not yet released the criteria for acceptance. But given broad participation is the goal, the criteria should be very welcoming.

Indeed, Cuomo says the only reason many blockchains are “private” is because there are nowhere to list them. Launching and growing new networks and applications requires global awareness. IBM aims to create that visibility for networks no one knows exist. And doing so should address some key problems for blockchain visibility and interoperability.

The Unbounded Registry will reserve names for networks, applications, and consortiums. It will improve the discoverability of blockchain networks and applications. The catalog will organize registries by domain-specific functions and services. And all of it will reside on an independent, open and shared blockchain platform. At least, those are the ambitions of its creators.