Bosum

The ship's officer who actually gets the work done.

Bosum is a two-panel file manager in the Norton Commander tradition, built for developers. It comes as a terminal app (Rust + Ratatui) and a desktop app (Tauri + Svelte 5). Both run on one shared Rust core and read the same config file.

• Norton Commander at heart. Blue panels, F-key bar, command line, and NC's keys by default.
• Git in every panel. oh-my-posh style branch, ahead/behind, staged/modified/untracked counts and stashes, plus a glyph per file (Nerd Font, or ASCII).
• Search like Everything. Every file name on the machine sits in RAM and queries run in parallel: about 1.4M files index in ~0.2 s and answer in under 10 ms.
• See before you open. The desktop app previews over 60 file types: code, Markdown with Mermaid diagrams and math, Jupyter notebooks, Word, spreadsheets, PDFs, SQLite databases, JSON/YAML/TOML as trees, certificates, e-mail, calendars, EPUB books, fonts, images, video and audio, plus the git diff of any changed file. See the full list.
• Plays well with the desktop. Delete goes to the trash, folders refresh themselves, files drag to and from other apps, and Ctrl+C / Ctrl+V share files with your other file manager.
• Configurable. Key bindings, color schemes, glyphs, user menu and fonts all live in one TOML file.

Find file: every file on the machine, in milliseconds	Desktop app: sidebar, tabs, color tags, git
Thumbnails (Alt+V) with the preview pane (Space)	PDFs preview in place; the left pane shows git status
Archives list their contents; Ctrl+E extracts them	Miller columns and preview, light theme

The preview pane (Space): Markdown with a Mermaid diagram and math, a Jupyter notebook, a spreadsheet, a Word document and a font.

YAML as a tree, a SQLite database's tables, a certificate about to expire, and an e-mail.

A calendar, the git diff of a changed file, a log colored by level, and an EPUB book.

Install

Terminal app, one command:

brew install mwo-dk/bosum/bosum                                                    # macOS, Linux
scoop bucket add bosum https://github.com/mwo-dk/scoop-bosum; scoop install bosum   # Windows
cargo install bosum                                                                # anywhere with Rust

Desktop app (macOS, Linux x86-64): brew install --cask mwo-dk/bosum/bosum-gui

Download: pick your platform under Releases. The builds are not code-signed; the release notes say how to get past the first-run warning on Windows and macOS.

Both apps check once a day for a newer release and tell you the command that upgrades your copy (brew upgrade, scoop update, cargo install, ...), or link to the download.

Build from source:

git clone https://github.com/mwo-dk/bosum.git
cd bosum
./install/install.sh                                          # Linux, macOS
powershell -ExecutionPolicy Bypass -File install\install.ps1  # Windows

The script offers to install Rust and Node.js when they are missing, and asks first. See install/INSTALL.md. For development: cargo run -p bosum, or cd gui && npm ci && npx tauri dev.

Git glyphs need a Nerd Font. In the terminal, use one as your terminal font; the GUI picks up any installed Nerd Font listed in gui.icon_font. Without one, set glyphs = "ascii".

Keys (defaults)

Typing goes to the command line. Enter runs it in the panel's directory, and cd works. Both apps support the mouse: click, double-click, right-click to mark, and the wheel. The GUI also does Shift-click ranges, drag-and-drop between panels, and clickable column headers and paths.

Using Bosum

Start either app with up to two folders: bosum ~/src ~/Downloads or bosum-gui .. A file opens its folder with the cursor on it, so bosum-gui ~/Pictures/cat.jpg shows that picture. Without arguments both panels open in the current folder (the desktop app restores your last session).

The NC way. One panel is active. Move with the arrows, Enter opens a folder or file, and Backspace goes up. Mark files with Insert (or + with a pattern like *.rs), then F5 copies or F6 moves them to the other panel's folder. With nothing marked, the file under the cursor is used. F3 views, F4 opens your $EDITOR, F8 moves to the trash (after asking), and Shift+F8 deletes for good. F9 opens a searchable list of every command, so you never need to remember a key.

Reading the git line. Inside a repository the panel's bottom line shows the branch, commits ahead/behind the upstream, and counts of staged, modified and untracked files and stashes. Each file and folder gets the same glyph, so a changed file deep in src/ marks src too. Ignored files get a crossed-out eye.

Find file (Alt+F7 or Ctrl+F). Start typing; results update per key. Enter jumps to the file with the cursor on it, F3 and F4 view and edit it in place, and Tab limits the search to the current folder. The first start builds the index in the background; after that it is loaded from disk and kept current while Bosum runs.

Desktop app extras (all rebindable, like everything else):

The preview pane (Space) follows the cursor. At a glance:

docs/previews.md lists every format, what it shows and how it works. Where there is a choice, buttons at the top of the preview pick it, and the choice sticks. Ctrl+O, or the button next to the view switcher, toggles one or two panes.

Columns and folder sizes. Right-click the column header (or F9, "Columns and folder sizes") to add Files and Created columns or hide Type, and to turn on automatic folder sizes: every folder is measured as you open its parent, in the background.

Folders reread themselves when something changes in them. Drag files to the other pane, to another application, or in from one; Bosum asks whether to copy or move.

The sidebar holds places, drives with free space, favorite groups (right-click a group, then "Add current folder") and the git repositories you visited recently. Pick a theme from the F9 command list (type "theme").

Find file

Alt+F7 or Ctrl+F opens it in both apps. Results update as you type.

Alt+letter is the other, smaller search: it jumps to the first name in the current panel starting with that letter. Keep typing to narrow it; Backspace takes a letter back, Esc ends it.

The desktop app lists the first 500 hits and counts the rest; type more to narrow them down.

Everything's syntax:

Configuration

bosum --config-path shows where the file lives (~/.config/bosum/config.toml on Linux). bosum --dump-config prints every option with its default. Set only what you want to change:

theme = "midnight"          # or "nc", or your own [themes.<name>]
glyphs = "nerd"             # or "ascii"
editor = "hx"               # else $VISUAL / $EDITOR

[keys]
quit = ["F10", "Ctrl+Q"]    # listing an action replaces its default keys
search = ["Ctrl+P"]

[themes.mine.panel]         # unset slots fall back to the NC scheme
fg = "#e0e0e0"
bg = "#101820"

[[user_menu]]               # F2; %f file, %d dir, %s selection (shell-quoted)
key = "t"
label = "cargo test"
command = "cargo test"
wait = true

[search]
exclude = ["/proc", "/sys", "node_modules"]   # a path skips a tree; a bare name skips every such directory
watch = true

[gui]
font_size = 15

How search stays fast

The index (crates/bosum-core/src/index.rs) keeps each name once in a \0-separated byte buffer, with a 12-byte node per entry (parent, offset, length, flags). A query runs a single SIMD memmem scan over that buffer, split across all cores. Full paths are built only for hits. The index is saved to the cache directory, so it loads in ~90 ms on the next start. It is then rebuilt in the background and kept current by file system events (inotify, FSEvents, ReadDirectoryChangesW).

Run cargo run --release -p bosum-core --example bench -- / to measure it on your machine.

Known limits and upgrade paths:

• Linux: inotify needs one watch per directory. Past fs.inotify.max_user_watches, the hourly rebuild catches changes. fanotify would remove that limit, but it needs root.
• Windows: the first index comes from a directory walk. Reading the MFT and USN journal directly, as Everything does, would make cold starts faster.

Layout

crates/bosum-core   config, fs ops, git status, search index (shared)
crates/bosum        terminal UI (package and binary: bosum)
gui/                Svelte 5 frontend
gui/src-tauri       Tauri backend (binary: bosum-gui)

License

MIT

Norton Commander is a trademark of Gen Digital Inc. Bosum is an independent project, not affiliated with or endorsed by Gen Digital.