I have, but looking at their website doesn't get me closer to an answer to my question.

They describe themselves as "Enabling developers, enterprises, and organizations to collaboratively build, share, and enhance blockchain frameworks and tools."

So Hyperledger sounds like a framework/platform for building blockchains?

So I'm wondering what blockchains have been built with it, and made it past the prototype stage to be in use in the real world?

There's a link to a bunch of companies that use it on their site. I haven't really gotten into the details of what they do with it.

If you're really interested, take a look at all the things Tezos is being used for, mostly in France. I don't personally get into this stuff, but there are things happening. Tezos doesn't meet your criteria as it does have a coin, but it's more of a utility coin than others.

https://tokenist.com/securitize-and-elevated-returns-to-toke... https://xtz.news/adoption/a-total-asset-value-of-1-billion-e...

https://xtz.news/adoption/fraktion-a-brand-new-fractional-re...

https://decrypt.co/43934/a-city-in-france-uses-tezos-blockch...

Thanks for the links to examples.

These voting and real estate securitisation projects look to be quite small-scale, but they also seem to be real-world and not prototypes, so they are what I asked for :)

no worries!

I think this stuff is still very much in its infancy. I look forward to seeing more as time goes on -- the Tezos community has always seemed more focused on this than "price price price" like some others.