I've been using this search engine and I have to say I'm absolutely in love with it.
Search results are great, Google level even. Can't tell you how happy I am after trying multiple privacy oriented engines and always feeling underwhelmed with them.
It means that they are open sourcing an increasing number of components? In the very same page they are linked: browser extensions, libraries they use for their AI features.
That's the problem, though, given the cost of indexing it. I'm not sure there's a single open source search engine that doesn't rely on some sort of proprietary software. My philosophy is that if the product is free, you likely are the product.? We would almost need a donation-based search engine to get around that, which would likely would not be sustainable.