A suite of fast, opinionated terminal tools written in Rust. Single static binaries. Shared TUI foundation (crust). No runtime dependencies.

Landing page: isene.github.io/fe2o3

This repo also holds fe2o3 itself: the suite as a grid of cards, one per app, with its logo, what it is and one line on why. Arrow keys move, Enter runs it in the same terminal, ? shows that app's own help, w opens its repo, / filters.

It is also the installer. What you have has a solid frame and a green ✓; what you do not have is dashed with an amber ↓. i fetches the one under the cursor, I fetches every missing one in view — so you can take the launcher alone and pick up only the apps you fancy. Binaries land in ~/bin if you have it, else ~/.local/bin. A ~/bin/<tool> that is a symlink to a local build is left alone.

cargo build --release        # or grab the binary from Releases
fe2o3                        # the grid
fe2o3 -l                     # the suite as plain text

Adding an app to the suite is one command:

tools/add-app isotopes --kind "Chart of the Nuclides" --group Science \
  --blurb "3,386 isotopes, how they decay and what into" \
  --desc "Neutrons across, protons up, coloured by how each one comes apart."

That writes the launcher row, renders the card logo from the app's own SVG, adds the table rows here and in CLAUDE.md, puts a card on the landing page in the right group with the count bumped, and drops a release workflow into the app's repo if it has none. --check shows what it would do; running it twice changes nothing the second time.

Tool	Release	Role	Ruby equivalent
pointer		File manager	RTFM
kastrup		Messaging hub (email, RSS, chat)	Heathrow
scribe		Modal text editor for writers	—
scroll		Web browser	brrowser
gazette		Daily news digest reader	—
tock		Calendar with ephemeris	Timely
astro		Astronomy panel + telescope/eyepiece catalog	astropanel + telescope-term
watchit		Movie / series browser	IMDB-terminal
torii		Captive-portal listener (NetworkManager → Firefox)	—
prism		TUI color picker (FG/BG slots, RGB+HSV, WCAG contrast)	—
fonts		TUI font picker with live previews (enumerates installed fonts via glyph); returns family + size	—
drain		Battery-drain triage TUI (top wakers, per-WS attribution)	—
amar		Amar RPG companion (NPC / encounter / town / weather forge, campaign tracker, lore, AI inspire)	Amar-Tools
tune		Spotify Connect controller (search, library, queue, devices, transport)	—
melody		Melody maker — piano-roll play / record / edit, metronome, WAV export	—
petri		Petri net player — load a net, fire transitions, watch conflicts, find deadlocks	—
library		Generative personal library (curate a shelf of books that should exist, then have them written on demand)	—
grid		AI-native spreadsheet (csv/xlsx/ods, formula engine, Claude editing)	—
viewer		Universal file viewer (tables, docs, slides, pdf, images, code; launches the right editor)	—
CC-sessions		Claude Code session manager (cc/cl: bookmark + resume sessions with tags, /bm command)	CC-sessions ≤1.5 (Ruby)
rpnx		RPN / XRPN scientific calculator (HP-41 stack, cycling shift pages, runs XRPN programs)	T-REX
typo		Touch-typing tutor (strict drills, live WPM/accuracy, US + Norwegian layouts)	—
elements		Periodic table explorer (118 elements + hypothesized 119–126, full Wikipedia article per element, offline)	—
isotopes		Chart of the nuclides (3,386 isotopes, decay modes, half-lives, decay chains)	—
stars		Hertzsprung-Russell diagram explorer (461 named stars, evolutionary tracks, full Wikipedia article per star, and a sky map to pick from)	—
particles		Standard Model explorer (17 fundamental particles + proton/neutron, and a rotatable zoom from atom to quark)	—
exoplanets		The known exoplanets (6,309 worlds by orbit and size, systems, habitable zones)	—
fractal		Chaos and fractals in braille (Mandelbrot, Julia, logistic map, Lorenz, Hénon)	—

Superseded by the assembly tools in CHasm, which do the same job with a fraction of the cycles.

Tool	Release	Was	Replaced by
rush		Interactive shell	bare
crush		Configuration TUI for rush	bareconf

nova and scope have been merged into astro and are archived. hyper has been folded into scribe — .hl editing now lives there with full hyperlist.vim parity. All three READMEs link to their replacements.

Crate	Release	Role	Ruby equivalent
crust		TUI foundation (panes, colors, input)	rcurses
glow		Inline images (kitty / sixel / w3m / braille)	termpix
highlight		Theme-aware syntax highlighter (~18 source langs + HL / Markdown / LaTeX / email)	—
orbit		Moon phases, ephemeris, sun / planet positions	ephemeris
starmap		The naked-eye sky in braille (9,096 stars with distances, constellation figures, star picker)	—
plot		Terminal charts (sparkline / line / candle / bar) with Unicode + ANSI	termchart
fe2o3-rpnx-core		RPN / XRPN calculator engine shared by rpnx (TUI) + the RPNx phone app	—

The mobile half of the family. nomad is a single Android monorepo — a shared Rust core (the same logic as the desktop, via UniFFI) under thin Kotlin / Compose shells. Each app carries one Fe₂O₃ workflow off the laptop and syncs its data over Syncthing — no Google account, no cloud middleman.

Get the launcher, then let it fetch the rest: press I in the grid and every app you do not have is downloaded.

curl -L "https://github.com/isene/fe2o3/releases/latest/download/fe2o3-linux-x86_64" \
  -o ~/bin/fe2o3 && chmod +x ~/bin/fe2o3
fe2o3          # then press I

# Other platforms: replace -linux-x86_64 with:
#   -linux-aarch64   (Raspberry Pi, ARM64 Linux)
#   -macos-x86_64    (Intel Mac)
#   -macos-aarch64   (Apple Silicon)

Or grab them all straight from the shell:

for app in pointer kastrup scribe scroll gazette tock astro watchit torii prism fonts drain amar tune melody petri library grid viewer rpnx typo fractal elements isotopes exoplanets stars particles; do
  curl -L "https://github.com/isene/$app/releases/latest/download/$app-linux-x86_64" \
    -o ~/bin/$app && chmod +x ~/bin/$app
done

Rust the language was actually named after a family of fungi (Pucciniales, plant pathogens "over-engineered for survival" per Graydon Hoare). The iron-oxide association came later, through the visual rhyme with what those fungi look like on a leaf. Fe₂O₃ is that iron oxide: what happens when iron meets oxygen meets time. This is the terminal-facing half of that toolkit.

Every tool is a feature port of a long-running Ruby original, rewritten for speed, single-binary distribution, and async-first UI behavior.

All tools in the suite are public domain (Unlicense). Borrow or steal whatever you want.

— Geir Isene