bible-rs

Bible: a very fast, native Bible reader for the Mac, written in Rust. Just the Bible — beautifully typeset, searchable as you type, with highlights, notes and bookmarks kept on your computer. The iPhone version shares the same core.

• Instant. The first frame already shows the text — about 15 ms of work on top of opening a window; full-text search across the whole Bible in under 2 ms (most queries well under 1 ms); scrolling costs ~0.2 ms of CPU per frame. Numbers below.
• Typeset for reading. Literata serif, a comfortable measure, superscript verse numbers, chapter and section headings, poetry with hanging indents, LORD in small capitals, optional red letters, paragraphs or verse-per-line, adjustable size, light / sepia / dark.
• Seven public-domain translations built in (KJV, WEB, BSB, ASV, YLT, Darby, Webster), side by side in parallel columns or one verse across all of them. Add the NLT and the NET Bible free in one click, the ESV with a free key, others with an API.Bible key or a file you own (which translations, and how).
• Keyboard-first. ⌘K jumps anywhere (jn 3:16, Rom 8, 1co13, even revalation 21), ← → turn chapters, ⌘F searches, ⌘[ ⌘] go back and forward, 1–6 highlight.
• Yours. Highlights, notes and bookmarks live in a local SQLite file and export to JSON or Markdown. No accounts, no feeds, no network unless you add an online translation.

Reading

• Continuous scrolling through all 1,189 chapters — only what is on screen is ever typeset.
• Paragraph mode (verses flow inside paragraphs, first-line indents) or verse-per-line (numbers in the margin); poetry keeps its line structure in both.
• Book titles, chapter headings, section headings and Psalm superscriptions where the translation has them; words of Christ in red (⌘R); KJV translator additions in italics.
• Text size (⌘+ ⌘− ⌘0), line spacing, line length, justification, verse numbers and headings are all adjustable; light, sepia and dark themes (⌘⇧L).
• Remembers where you were.

Navigation

• ⌘K palette: references with fuzzy book names and typos, recent places, translations, commands.
• Book/chapter picker in the toolbar and the sidebar (⌘B).
• Back/forward history (⌘[ ⌘], ⌥← ⌥→), previous/next chapter (← →).

Search (⌘F)

• Results update as you type; every word must appear (word prefixes by default, or whole words).
• "exact phrase", -excluded words, whole Bible / Old Testament / New Testament / one book.
• Matches highlighted in the results; ↑ ↓ and ⏎ jump to the verse, which flashes.

Study

• Click a verse (⇧-click for a range, J/K to move) to select it, then: highlight in six colours (1–6, 0 to clear), write a note (N), bookmark (B / ⌘D), copy (⌘C, or ⇧⌘C with the reference) or compare translations (C). Right-click opens the verse menu with all of these.
• Notes and bookmarks show in the margin; the Study sidebar lists everything.
• Export to Markdown (⌘E) or JSON (⌘⇧E); JSON imports back.

Translations

• Instant switching (⌘1…⌘9 or the toolbar), parallel columns (⌘⇧P) aligned verse by verse, and a compare view showing one verse in every installed translation.

Mac

• Native menu bar, unified title bar, Metal rendering on the low-power GPU, app icon, scripts/bundle-macos.sh → .app + .dmg.

All seven come from eBible.org's USFM editions; download URLs and SHA-256 digests are pinned in xtask/src/main.rs and the data is rebuilt with cargo run -p xtask -- build-data. Provenance, licence statements and what was deliberately left out are in LICENSES/.

Copyrighted translations (NLT, NASB, LSB, ESV, NIV, …) are never part of this repository — no text, no derived index, no test fixtures. You can add them yourself in either of two ways.

Settings (⌘,) → Translations → Import file… / Import folder… (or ⌘I), or from a terminal:

bible-rs import ~/Downloads/MyBible.zip --abbrev NASB --name "New American Standard Bible"

Supported formats:

The text is converted to bible-rs's format and stored only in your data folder (~/Library/Application Support/bible-rs/translations/ on macOS). Deuterocanonical books are skipped. Remove an import from the same settings page or with bible-rs remove <id>.

Chapters are fetched from each publisher's own API as you read, and shown with the publisher's notice (which links to their site, as their terms ask). TRANSLATIONS.md covers every major modern translation: how to get it free, or why it has to be bought.

1. Settings (⌘,) → Translations → Online translations.
2. NLT and NET: click Add NLT or Add NET. ESV: Get Free Key… opens api.esv.org; paste the key and click Add ESV. API.Bible: paste your key, click List My Bibles…, and Add the ones you want. Keys are stored in the macOS Keychain (on Linux, a secrets.json that only you can read).
3. Pick the translation like any other, alone or in parallel columns.

What is stored locally follows each API's terms:

• NLT API. 50 verses a request and 500 requests a day without a key (500 and 5,000 with one). Longer chapters are fetched in several ranges, requests are spaced at least a second apart, and the day's count is kept so the limit is never passed. At most 500 verses are kept on disk, and never a complete book.
• NET Bible API. Requests are spaced at least a second apart. The NET's terms set no storage limit, so fetched chapters are kept for 30 days.
• ESV API. At most 500 verses and never more than half of any book are kept on disk. The oldest chapters go first, and a one-chapter book is shown but not stored. Requests are spaced at least a second apart (the limit is 60 a minute).
• API.Bible. Fewer than 500 consecutive verses are cached, and nothing older than 14 days is used. The copyright returned with each chapter is shown with API.Bible's citation, and each displayed chapter is reported through API.Bible's Fair Use Management System (FUMS) with an anonymous device id.

Full-text search covers local translations (bundled and imported). Online translations are read chapter by chapter, and appear in parallel and compare views as their chapters load.

⌘/ shows them in the app:

Measured on the machine bible-rs was built on: a headless Ubuntu VPS (AMD EPYC 7B13, 16 vCPUs) with no GPU — the app runs under Xvfb with Mesa's llvmpipe software OpenGL, so window and frame timings are pessimistic compared with a Mac. Criterion medians (cargo bench); startup is the median of 15 launches (scripts/bench-startup.sh). macOS numbers from CI are further down.

Startup — target: first painted text in under 150 ms

The first frame always contains the text. While the window and OpenGL context are created (~100 ms here, almost all of it software GL), the translation being read is decoded on a background thread (~25 ms; its search corpus is built later, after the first frame); frame 0 then typesets the visible chapter (2–7 ms). Under software rendering the empty-window floor alone is 146 ms, so presentation lands just over the target here; the app's own work fits in ~15 ms.

Search — target: under 10 ms. KJV, 31,102 verses, whole Bible unless noted.

Scrolling — target: 60 fps or better. 900 frames scripted at ~2,200 px/s through 13 consecutive chapters:

The p99 frames are the ones where a new chapter scrolls into view and is typeset; even those stay well inside a 120 Hz frame (8.3 ms). Chapters next to the reading position are typeset while idle.

Typesetting one chapter (uncached, default settings):

Everything else

The macOS CI job runs the same probes against the bundled app with both renderers. GitHub's macos-latest runner is a virtual machine with a paravirtualized GPU and display, so absolute window timings are far slower than a real Mac and vary a lot between runs; compare each column with the empty-window baseline measured alongside it. Medians of 10 launches:

Startup trace for the Metal build on that runner: window and Metal context ready at 207 ms, first frame built at 218 ms — bible-rs's own work before the first paint is ~11 ms (John 1 typeset in 4.3 ms); everything before that is the machine creating a window. OpenGL's 15 fps while scrolling is why macOS renders with Metal. Final numbers on real Mac hardware are still to be taken; scripts/bench-startup.sh measures them, including the empty-window floor.

Sidebar. Opening and closing the sidebar slides it on a spring that comes to rest in 265 ms. At the default width the text column keeps its measure and only moves; narrower windows reflow the chapter on screen once per frame. On a MacBook Pro (M4 Pro, 120 Hz built-in display), 8 slides per scenario with scripts/bench-sidebar.sh:

Reproduce with:

cargo bench -p bible-core          # search, decoding, references, SQLite
cargo bench -p bible-rs            # chapter typesetting
scripts/bench-startup.sh           # launch → first frame (vs. an empty window), 900-frame scroll run
scripts/bench-sidebar.sh           # sidebar open/close: frame pacing, UI time, chapters typeset per slide
bible-rs search "love one another" # prints the query time

Requires Rust 1.95+, the minimum egui 0.36 supports.

# Linux needs: libxkbcommon-dev libgl1-mesa-dev libwayland-dev libx11-dev
cargo build --release
./target/release/bible-rs

On macOS, scripts/bundle-macos.sh builds dist/Bible.app (UNIVERSAL=1 for arm64 + x86_64, SIGN_IDENTITY=… to sign). scripts/release-macos.sh makes the downloadable release: the universal app signed with a Developer ID and notarized, a disk image, a zip, their checksums and the signed update feed that installed copies check with Sparkle (RELEASING.md). CI builds an ad-hoc signed DMG on every push and uploads it as an artifact.

Other tasks:

The binary doubles as a small CLI:

bible-rs read "jn 3:16-18" --translation web
bible-rs search '"in the beginning"' --scope nt
bible-rs list
bible-rs import path/to/module.zip [--abbrev X --name "…" --key UNLOCK]
bible-rs export --markdown -o notes.md
bible-rs import-notes notes.json

apps/ios is the iPhone app (iPad runs it too): SwiftUI around the same Rust core, through UniFFI (crates/ffi). It has the Mac's typesetting, themes and colours. You can scroll through all 1,189 chapters, jump to a reference (jn 3:16), search as you type, and highlight, annotate, bookmark, copy or share verses. Parallel and compare views, import and online translations are Mac-only for now.

Requires Xcode 26 (the app targets iOS 17+), XcodeGen (brew install xcodegen) and rustup; the script adds the iOS Rust targets.

scripts/build-ios.sh --run        # build, then launch in a simulator
scripts/build-ios.sh --test       # UI tests in a simulator
scripts/build-ios.sh --framework  # just the Rust framework and the Xcode project, then:
open apps/ios/Bible.xcodeproj
scripts/ios-screenshots.sh        # regenerate docs/screenshots/ios/
scripts/ios-screenshots.sh --app-store  # full-size iPhone and iPad sets for the App Store

--run and --test use a simulator named "Bible iPhone", created if needed; set SIMULATOR="iPhone 17 Pro" to use another. Simulator builds need no signing. For a device, create apps/ios/Config/Local.xcconfig (git-ignored) with DEVELOPMENT_TEAM = <your team ID>, and BIBLE_BUNDLE_ID = <your bundle ID> if you don't own the default one. Then run scripts/build-ios.sh --device or run from Xcode.

scripts/release-ios.sh archives, signs and uploads a build for the App Store. apps/ios/APP_STORE.md covers the setup, the listing and the answers App Store Connect asks for.

crates/core   bible-core: canonical book grid, verse-indexed model, .bbl format, USFM/OSIS/
              Zefania/SWORD importers, search, reference parsing, SQLite study store,
              ESV/API.Bible providers, Keychain secrets, translation library
crates/app    bible-rs: egui app — reader (typesetting, continuous scroll), sidebar, palette,
              panels, settings, macOS menu bar, CLI
crates/ffi    bible-ffi: the core for mobile apps through UniFFI — chapters as styled blocks,
              search, references, study data, design tokens
apps/ios      the iPhone app: SwiftUI, with a UIKit/TextKit reader; XcodeGen project.yml
xtask         reproducible bundled-data build from pinned public-domain sources
data          generated .bbl files (public domain only)

See DECISIONS.md for why egui, how typesetting and continuous scrolling work, the data format, search, and the licensing approach.

Code: MIT (LICENSE). Bundled translations: public domain (LICENSES/). Fonts: Literata and Inter, SIL Open Font License 1.1.