"Unfortunately, [the terms] leaked into the documentation that everyone reads" - We did this on purpose to align everyone's terms. It makes things so much easier when the people asking and answering questions are using the same language.
"The official JSON Schema website has a validator you can try: https://www.jsonschemavalidator.net/" - Would have been better to point to the actual official JSON Schema website's tools page (https://json-schema.org/tools) that lists many online validators.
There are some interesting conceptions of OpenAPI in here as well. Specifically, OpenAPI isn't a JSON Schema document. It's its own kind of document that has JSON Schemas embedded in it.
Still, it's a decent high-level summary. If you're interested in diving a bit deeper, definitely come visit us in Slack (https://json-schema.org/slack).
I'm in the process of writing a toolchain of sorts, with the OpenAPI document as an abstract syntax tree that goes through various passes (parsing, validation, aggregation, analysis, transformation, serialization...). My immediate use-case is generating C++ type/class headers from component schemas, with the intent to eventually auto-generate as much code as I can from a single source of truth specification (like binding these generated C++ data classes with serializers/deserializers, generating a command-line interface...).
JSON schema is so flexible that I have several passes to normalize/canonicalize the component schemas of an OpenAPI document into something that I can then project into the C++ language. It works, but this was significantly trickier to accomplish than I anticipated.
Now it feels like writing a validator is extremely complicated.
IMO, the built-in vocabularies were enough, and keeping it simple would provide more value.
JSON as a format didn't win because it supported binary number encoding or could be extended with custom data types -- but rather because it couldn't.
However, we already had an XMLSpy license, so decided to just stick with designing XSDs in XMLSpy and then just translate that to JSON Schema.
If you make some small decisions, like value with attributes becomes an object, you can get a fairy decent subset of XSD to map 1:1 onto JSON Schema 2020-12.
As a nice side effect of writing the XSD to JSON Schema converter, it's trivial for us to support reading XMLs and convert that to JSON. Great for the customers who have programs that doesn't speak JSON.
For example, the following issues pass under the metaschema.
{"foo": {"bar": { ... }}} # wrong
{"foo": {"type": "object", "properties": {"bar": { ... }}}} # correct
{"additional_properties": false} # wrong
{"additionalProperties": false} # correctJSON Schema could get more traction if its homepage was oriented more towards users instead of implementors.
*even if I would prefer more transformation/conversion features that would bring it to more more a parser rather than only a validator
I've been exploring how this generalizes beyond side effects. Every React state library creates a JavaScript copy of state that must sync with the DOM. This is the original sin. Two truths = lies.
The solution isn't better syncing, it's refusing to duplicate. The DOM is already a perfectly good state container. All you have to do is read it.
Releasing a paper (DATAOS) and React implementation (stateless, <1KB) soon. It's the architecture behind multicardz (hyper-performing kanban on steroids, rows AND columns, 1M+ cards, sub second searches, perfect lighthouse scores, zero state sync bugs). Because there's no state to sync.