smep — a Simple Markdown Editor & Previewer, written in Rust

smep is a markdown editor with live preview, built in pure Rust on the GPUI framework (the UI toolkit behind the Zed editor). A frameless window with a small menu bar in its title bar (hide it with a shortcut), and three views: source, split, and a rendered view you edit in place, block by block.

Status

0.1.2 is the third release: the frameless window with its view modes, in-place editing in the rendered view, opening files from the OS, a Homebrew formula, and typing that stays smooth in large documents (the Markdown parse runs off the keystroke). Expect rough edges; the editor and preview are built on gpui-kit and gpui-pre, which are themselves young.

What it does

• Source, split (resizable) or rendered view; the preview updates as you type.
• The rendered view edits in place: click a block and it turns into its Markdown source, sized to its text; click elsewhere or press Escape and it renders again. A click below the last block starts a new one; / there opens the block menu.
• Frameless window: File / Edit / View menus live in the title bar and can be hidden; full screen on a key.
• A menu of blocks (headings, lists, task list, quote, code block, table, divider, image, link) wherever you ask for it: type / on an empty line, click the + beside one, click below the end of the text, or right-click.
• Seven preview themes (System, GitHub, Newsprint, Night, Sepia, Solarized Light/Dark): right-click the preview. The choice is remembered in settings.toml under the platform config directory.
• Markdown highlighting in the editor from the same parser the preview uses.
• The preview follows the editor: whatever block is at the top of the editor is at the top of the preview.
• CommonMark + GFM: tables, task lists, strikethrough, footnotes. Raw HTML inside Markdown renders too, and .html files open straight into the HTML preview.
• Open, save, save as; an unsaved-changes prompt before closing.
• Light and dark, following the system.
• One static binary, no web view, no Electron.

Keys

Install

cargo install smep
smep notes.md

On a Mac or on Linux, Homebrew works too:

brew install newdee/tap/smep

The formula installs the release's own build (a universal app on macOS, run from the smep command) and follows new releases by itself. smep --version and smep --help print and exit without opening a window.

Building from source needs a Rust toolchain and, on Linux, a few system libraries; see docs/dev.md.

Make it the default for .md

• macOS: use the smep.app from a GitHub release, or the one Homebrew keeps at $(brew --prefix smep)/smep.app (a cargo install binary has no bundle, so Finder cannot pick it). Right-click a .md file, Get Info, Open with: smep, Change All. Files opened this way land in the running window. The releases are not yet signed with a Developer ID, so the first open from Finder needs right-click, Open.
• Windows: scripts\register-windows.ps1 adds smep to the "Open with" list (current user, no admin); then choose it once in Settings, Apps, Default apps, or right-click, Open with, Always.
• Linux: copy assets/smep.desktop to ~/.local/share/applications/ and run xdg-mime default smep.desktop text/markdown.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE)
• MIT license (LICENSE-MIT)

at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this work by you shall be dual licensed as above, without any additional terms or conditions.