Cue is interesting, but why is it only available as a command-line tool rather than a library? I'd want to integrate such a configuration language in my programs, so I could use its evaluation and validation capabilities rather than writing a custom parser/validator.
Also their website is terrible. One of those projects that assumes you've already decided (or been forced) to use it and have cleared out a week of your schedule to learn how to use it.
I learned cue from it during one weekend with plenty of time to play with kids, using it in production since 2020, it's been absolutely great, zero problems, very terse configs, intuitive formalism.
I took another look and eventually found the bit of the website that they should put front and centre in the Tutorial page. Still difficult to navigate (why doesn't the page tree show up on the left?) but it is at least well written and to the point.
The "learn more" button on the front page should link to that, perhaps with a single paragraph giving motivation.
And the main page breaks the fundamental rule of programming languages/formats. Put examples on the front page!
I assumed they hadn't done that because the examples would be too complex or maybe the concepts were too difficult to demonstrate with small examples but having gone through the tutorial that isn't there case at all.
I find specs nearly unreadable when trying to first digest a language; While invaluable for advanced usage and implementation, I can't read a BNF-Style Spec and make heads or tails of what's going on unless I also have an annotated example next to it.
