I see the author has published a successor to rwtxt: https://offlinenotepad.com/. Source: almost 2 years ago

In today's fast-paced tech world, giving effective presentations is crucial for conveying complex ideas and engaging audiences. While Markdown has emerged as a popular lightweight markup language for creating rich text documents, its use in creating dynamic, interactive, and visually appealing presentations can be challenging. This is where Marp comes into the picture - an open-source Markdown presentation app... - Source: dev.to / 3 months ago

It's just CommonMark, Gruber was ticked off enough that he declined to allow them to use the term Markdown at all. Alone among the variations, or nearly so, he's fine (as your link indicates) with Git-Flavored Markdown. The thing is, they didn't fork it, they decided to "standardize" it. John Gruber had already published a Markdown standard: https://daringfireball.net/projects/markdown/, and a reference... - Source: Hacker News / 3 months ago

Aha that's just an inline footnote, we support both in Supernotes. So you can quickly write ^[Name of Reference] (that will auto assign it the number 1 once rendered) rather than [^1] ... [1]: Name of Reference. Footnotes aren't part of the original Markdown specification (https://daringfireball.net/projects/markdown/). - Source: Hacker News / 3 months ago

Markdown is a text markup language. It's widely adapted. For example, github repo's will detect the readme.md file in the current directory and display it below. - Source: dev.to / 5 months ago

Note, that this file is a Markdown and YAML file at the same time, and as such human- and machine-readable, if the fields are filled carefully. - Source: dev.to / 6 months ago