A formal spec for GitHub Flavored Markdown

GitHub is now implementing a formal specification for GitHub Flavored Markdown (GFM) across all user-generated content on its platform, including comments, wikis, and repository files, to improve integration and preview capabilities for third-party software. This initiative is based on CommonMark, which aims to unify various Markdown dialects and includes custom features like tables, task lists, and autolinking specific to GitHub. The company has also open-sourced a reference implementation in C, derived from the original cmark parser, to support these features. The change is designed to align with existing real-world Markdown usage, so most GitHub documents should remain unaffected, although some with more obscure features might render differently. More details can be found in GitHub's Engineering Blog.