Apex piped through cat-and-render: tables, citations, and inline screenshots all visible at the command line.
A single Markdown processor that understands every flavor people actually write — and turns your terminal into something that can show the images they reference.
The Markdown ecosystem has spent fifteen years branching into incompatible dialects. CommonMark is strict, GitHub Flavored adds tables and task lists, MultiMarkdown adds citations and footnotes, Kramdown adds attribute syntax, Marked adds custom inclusion. Most tools pick one and ignore the rest. Apex picks all of them, and its parser figures out which extensions a given document uses without you flagging the dialect up front.
The party trick is image rendering. Pipe a .md file through apex in iTerm, Wezterm, or any ANSI-capable terminal and the inline  references actually render — not as link text, but as the image itself, scaled to the terminal’s character cells. It uses the iTerm2 inline-images protocol with a fallback to Sixel, so it works in most modern terminals and degrades gracefully in the rest. For a writer building documentation or drafting a blog post over SSH, that single feature changes how Markdown feels at the CLI.
Beyond rendering, it has the tools you’d expect from a complete processor: file inclusion ({{>partial.md}}), fenced divs for callouts, citation handling, plugin hooks for custom directives, and HTML/PDF/EPUB output paths. Brett Terpstra has been building Markdown tooling for the better part of a decade — Marked 2, MultiMarkdown helpers, the whole nv* family — and Apex feels like the consolidation of everything he’s learned about how people actually write Markdown.
Honest limitation: it’s a young project. The plugin API may shift, and a handful of MultiMarkdown edge cases around citation ordering aren’t quite right yet. The project is open source on GitHub if you want to track issues or contribute fixes.