JavaScript Markdown to HTML

• Showdown

  • Abandoned

• Pagedown

  • Maintained version of Showdown for Stack Overflow
  • No Markdown Extra features
  • No GitHub Flavored Markdown
  • Slowest markdown parser by far
  • Added fenced code blocks for GitHub syntax highlighting
  • Submitted patch for table support
  • Submitted h4-6 fix

• Marked

  • No Markdown Extra features (for example tables)
  • GitHub Flavored Markdown features broken or missing

• Sundown via Emscripten

• Great when it works

• More difficult to debug compared to hand written JavaScript

• Requires Typed Array support

• Faster than pagedown/showdown

// https://github.com/bootstraponline/livepreview_benchmark r41
emscript x 1.70 ops/sec ±4.02% (13 runs sampled)
pagedown x 0.27 ops/sec ±12.24% (6 runs sampled)
markdown deep x 4.54 ops/sec ±3.72% (28 runs sampled)
Fastest is markdown deep
Emscripten is 642% faster vs pagedown
Emscripten is 267% slower vs markdown deep

• js markdown extra

  • "possibility of entering infinite loop by some user input"
  • Regex from PHP not ported properly

• Markdown Deep

  • Almost full PHP Markdown Extra support
  • No GitHub markdown
    • Fenced code blocks only support ~~~ and not ```
    • No support for language in fenced code blocks for highlighting
  • Patches for missing gfm features in my fork
  • Not maintained (~1 year no updates)
  • Most complete hand written JS markdown lib
  • Faster than emscripten & pagedown/showdown

JavaScript HTML to Markdown

• to-markdown
  • No support for GitHub Flavored Markdown
• reMarked.js
  • Better support for GitHub Flavored Markdown

Markdown References

• https://github.com/suan/github-flavored-markdown-test/blob/master/README.md
• http://github.github.com/github-flavored-markdown/sample_content.html
• http://michelf.com/projects/php-markdown/extra/