commonmark is used in the swift compiler

[Gerald Bauer]

Hello,

    Good catch. Thanks for sharing. As always Apple copies Microsoft ;-)

   Microsoft's "new" open source Visual Studio Code [1]  has built-in
support for Markdown (e.g. highlighting, live preview, etc.) [2] and
is itself documented in Markdown [3] including the website.

   Cheers.

PS:  Apple is using ReStructuredText (RsT) for it's Swift docs.

[1] https://code.visualstudio.com
[2] https://code.visualstudio.com/docs/languages/markdown
[3] https://github.com/Microsoft/vscode-docs/blob/master/docs/languages/markdown.md