StepDown

StepDown is a small GNUstep/Cocoa Markdown viewer and creator written in Objective-C using Objective-C 1.0 style. It provides a split editor/preview window, file open/save/save-as, and live Markdown rendering without WebKit.

Features

• Create, edit, open, and save Markdown files.
• Live rendered preview using NSAttributedString.
• Basic Markdown support: headings, bullets, numbered lists, block quotes, code blocks, horizontal rules, links, inline code, bold, and italic text.
• Programmatic AppKit UI, with no nib or storyboard dependency.
• Manual retain/release memory management.

Screenshots

On macOS:

On GNUstep:

Generative AI disclosure

This app was created partly with Generative AI.

Build On GNUstep/Linux

Install GNUstep development packages, then run:

make

If your distribution uses GNUstep Make, this also works:

make -f GNUmakefile

Run:

./obj/StepDown

or, with GNUstep Make:

openapp ./StepDown.app

Build On macOS

Run:

make

Run:

open build/StepDown.app

Notes

The renderer is intentionally native and conservative rather than a complete CommonMark implementation. This keeps the application portable across Cocoa and GNUstep without requiring WebKit or external Markdown libraries.