[jrv]

I'm using CodeMirror 6 for https://promlens.com and together with the lezer parser generator, it was great for developing syntax highlighting, contextual autocompletion, and inline linting for PromQL (that part is OSS actually, in https://github.com/prometheus-community/codemirror-promql, much of it built by Augustin Husson, some by myself).