Writing a linter is fun: introducing Marcdouane

10-Jul-2026 11
The other day I had some inquiries about how markdownlint worked and ended up reading the code and not exactly liking all of it. Which is fair, because the project is a couple months short of being 14 year old and boasts above 16 millions total downloads on Rubygems. Some time ago I had this idea of writing my own linter so I went back to that folder and ended up coding away for the weekend, and using some great gems along the way which is why I'm writing this post and introducing another Markdown linter to the world: Marcdouane. What's in it? Not much, but it's backed by some really good gems that let you write the code that you need and not much more.
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