Nordstjernen Web Browser

Shared Web Workers, ElementInternals for form-associated custom elements, real popups that talk to their opener, <frame> documents, hardware VP9, AV1 and HEVC decoding through GStreamer, H.264 preferred wherever the operating system decodes it, an optional memory-safe Rust IPC parser, and a run of frame, CORS and cookie security fixes.

Video decoded by the operating system by default — Media Foundation on Windows, GStreamer on Linux — fonts loaded through the FontFace API, YouTube and Media Source fixes from Nordstjernen Sol, and security fixes for module-import CORS, cached security headers, HttpOnly cookies and frame sandboxing.

Behaviour is measured against the spec text, section by section, not against another browser — 141 spec rows fully implemented, 31 partial and 0 absent across WHATWG HTML sections 1–16. No element or API row is fully absent any more: every one is implemented, partial, or a deliberate non-goal. Against the Web Platform Tests (October 2026) it passes 91.5% of the html/, dom/, url/ and related subtests (151,974 of 166,164) and 73.2% of the css/ subtests (110,540 of 151,048), and QuickJS passes 82,243 of the 82,248 test262 tests it runs.

See docs/HTML-compatibility.md.

Secure.

Process-per-tab design — each tab runs in its own sandboxed renderer process, talking to the UI over IPC and shared-memory tiles. The renderer runs under seccomp + Landlock on Linux, a Seatbelt profile on macOS, and process mitigation policies on Windows · no JIT, in either the JavaScript or the WebAssembly engine.

Minimalism.

The core engine is about 245,000 lines of project C and headers, excluding the vendored libraries and generated assets — small enough for one person to read and audit end-to-end.

Capable.

JavaScript on QuickJS (an in-tree quickjs-ng fork with Temporal, the full Intl API and decorators in the engine, or Fabrice Bellard’s original QuickJS) with Canvas 2D, WebCrypto, Streams, Service Workers and the Navigation API · WebAssembly via WAMR’s fast interpreter · WebGL 1 & 2, and WebGPU on by default since 1.0.31 · inline <video> — MPEG-1, WebM through FFmpeg, and since 1.0.32 MP4 with H.264/AAC decoded by the operating system — with WebVTT captions, and HLS and DASH streams fed through Media Source Extensions · in-engine SVG · presentation MathML · CSS anchor positioning and scroll-driven animations · on-device safe browsing against a local blocklist.

Agent remote control.

Since 1.0.33, nordstjernen --mcp is a built-in MCP server that lets a local agent read and drive the browser window — tabs, a page outline, clicks, typing, screenshots and JavaScript. It is off until allowed in Settings, listens on loopback only, needs a token, and shows a toolbar badge while connected. The browser itself still has no AI assistant.

Prints.

Since 1.0.23, Ctrl+P lays the page out for paper and hands the sheets to the operating system's own print dialog — CUPS on Linux, the Win32 dialog on Windows, the Cocoa panel on macOS — so no printing code is written per platform and no dependency is added. @media print matches, @page sets the sheet size and its margins, and break-before, break-after and break-inside decide where a sheet may end. --dump=print:FILE renders the same pagination to a multi-page PDF without a printer. Since 1.0.24 printing works in the default process-per-tab mode, not only under --single-process.

Fast.

Desktop builds shape text through ns-pango, a Pango fork that caches finished glyph strings and font metrics across layouts — on a table-heavy page it serves 92% of shaping requests and cuts layout time by 24%. Regular-expression search skips positions that cannot start a match, the way V8's Irregexp does, and a page on an origin that does not speak QUIC is upgraded to HTTP/3 through the alt-svc cache instead of stalling on a connect timeout: Acid3 loads in 2.2 seconds rather than 15.5.

Private. No telemetry and no update pings.

Since 1.0.21 the client hints identify Nordstjernen as itself rather than impersonating Chrome, and --private starts a private-browsing session. Cookies are partitioned, and the safe-browsing check never leaves your machine.

Free software.

Since 1.0.28 Nordstjernen is dual-licensed: use, modify and redistribute it under the GNU GPL, version 3 or later, or under the Nordstjernen Source License 1.0, at your option.

the Northstar browser Northstar is the minimalist sibling of Nordstjernen: a single-window, single-page, single-process desktop browser built from the same clean-room C engine, licensed under the GNU GPL, version 3 or later.

It keeps the standards-first engine — lexbor, quickjs-ng (no JIT), ns-pango, WAMR, Wuffs — in about 188,000 lines of original C, with WebExtensions support, while leaving out tabs, per-tab renderer processes, WebGL and WebGPU: the page engine runs on its own thread inside the one browser process. It renders SVG in-engine, decodes WebP and APNG, plays MPEG-1 <video> and, since 1.0.13, streaming video through Media Source Extensions and plain MP4 and WebM files (AV1, VP9 or H.264 with AAC or Opus), prints through the system print dialog, and greets you with a sunny ark comic and a classic Mozilla-style toolbar. It runs on Linux, macOS and Windows — on Windows from the Microsoft Store — behind a Landlock filesystem sandbox and a default-deny seccomp filter on Linux, which since 1.0.15 also refuses executable memory wherever page content runs.

Rather than starting from an empty repository, it started from the working browser: the Nordstjernen C codebase, its full history included, trimmed to the desktop (Linux, Windows, macOS, FreeBSD and NetBSD) and ported to Rust module by module while it kept running. In October 2026 the last of the project’s C went, the QuickJS-ng engine included: all of Southstar’s own code is now Rust — about 330,000 lines in some 145 crates — and C remains only in the system libraries it links.