MarsFlow is a privacy-focused desktop browser — a fork of Firefox ESR with a Zen-inspired interface, DuckDuckGo search, and an optional Tor mode (onion routing, not a VPN).
| Engine | Gecko (Firefox ESR 153.0esr) |
| Platforms | Windows · macOS · Linux |
| License | MPL-2.0 |
| Repo | HARLEQU1IN/marsflowbrowser |
MarsFlow is independent and not affiliated with Mozilla or The Tor Project.
- Familiar web: sites and Firefox extensions work because we ship Gecko.
- Calm UI: vertical tabs, workspaces, compact sidebar — built in-house (not a Zen code fork).
- Search choice: Firefox search defaults + DuckDuckGo.
- Tor mode: one-click onion routing via bundled Tor Expert Bundle.
- Honest privacy: strong defaults, no false “total anonymity” claims.
| Phase | Feature | State |
|---|---|---|
| 0 | Repo & overlay scaffold | done |
| 1 | ESR bootstrap / branding pipeline | ready (local build required) |
| 2 | Search, start page, about:marsflow | done (overlay) |
| 3 | Vertical tabs + workspaces | done (overlay modules) |
| 4 | Tor mode manager + UI | done (overlay) |
| 5 | CI for win/mac/linux | workflows present |
A full browser binary requires compiling Firefox ESR (tens of GB disk, hours of CPU). See docs/BUILD.md.
# Preview the chrome UI in any browser (no Firefox build needed)
start ui-preview/index.html # Windows# 1. Clone this repo
git clone https://github.com/HARLEQU1IN/marsflowbrowser.git
cd marsflowbrowser
# 2. Fetch Firefox ESR source and apply MarsFlow overlay
# Windows (PowerShell):
.\scripts\bootstrap.ps1
.\scripts\apply-overlay.ps1
.\scripts\build.ps1
# macOS / Linux:
./scripts/bootstrap.sh
./scripts/apply-overlay.sh
./scripts/build.shPinned ESR version: see marsflow/config/esr-version.json.
marsflow/ # Our overlay (applied onto Firefox source)
branding/ # App name, icons, strings
prefs/ # Default prefs (privacy, search, Tor hooks)
searchplugins/ # DuckDuckGo + Firefox search
browser/components/ # Vertical tabs, workspaces, Tor UI
patches/ # Unified diffs against ESR
tor/ # torrc templates
scripts/ # Bootstrap, apply, build, package, fetch-tor
.github/workflows/ # Cross-platform CI
Tor mode starts a local Tor daemon and routes browser traffic through SOCKS5. It is onion routing, not a commercial VPN. Read docs/TOR.md.
- Signed installers (Authenticode / Apple notarization)
- Stronger Tor anti-fingerprinting alignment
- Split view & theme store
- Auto-update channel
Issues and PRs welcome. Keep changes in marsflow/ and scripts/ unless an ESR patch is required.