The modern web, on a 25-year-old Mac.

MacSurf is a web browser for Classic Mac OS 9 PowerPC.
Real CSS3. Real ES5 JavaScript. Real PNGs with alpha. Running on a beige G3.

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Why MacSurf exists

The web outgrew Classic Mac OS twenty years ago. Modern HTTPS killed it for good around 2016. Today, an out-of-the-box G3 or G4 running OS 9 can barely reach a single live website.

MacSurf brings the real web back. Not a screenshot proxy. Not a remote terminal session. A native browser, built with the tools that were on the platform — CodeWarrior, the Carbon API, QuickDraw, Open Transport — running real CSS3 layouts and real JavaScript inside the 64-megabyte memory floor of a 1999 iMac.

It is, as far as we can find, the first serious NetSurf port to Classic Mac OS, and the first browser shipped on Mac OS 9 with native CSS Grid, CSS custom properties, and ES5 JavaScript.

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The progression

Each shot below is a real milestone, captured on a Power Macintosh G3 running Mac OS 9. The fix-number annotations match this repo's commit history.

v0.2 — JavaScript on Mac OS 9 First real-world JS-bearing page. Duktape 2.7.0 ES5 evaluating live: Math.sqrt, JSON, ES5 array methods.	fixes73 — CSS transforms Native transform: rotate() / scale() / translate(). Integer Q15 sin/cos table, no FPU dependency — arbitrary angles on QuickDraw.
fixes74d — radial gradients 2-stop radial gradients via concentric PaintOval stack. 16 levels smeared on decode. Shape + position keywords parsed.	fixes77 — CSS animations Linear ping-pong animation player on top of fixes73 rotation. Wiggle, swing, and full 0°→359° spin.
fixes79b — PNG transparency QuickTime Graphics Importer feeding the NetSurf image content handler. PNG + GIF + BMP, all with real transparency.	fixes136 — word-break / overflow-wrap word-break: break-all, keep-all, white-space: nowrap, legacy word-wrap: break-word. URL-style aggressive wrapping.
fixes147 — stacking contexts CSS 2.1 painting order. Opacity, transforms, and explicit z-index all create new stacking contexts — properly painted on real hardware.	fixes151 — CSS Grid column placement grid-column: span N, 1 / -1 full-row hero, positional start / end, span + auto-wrap. Real Grid layout on OS 9.

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What's in the box

Component	Language	Purpose
browser/	C (C89, CW8)	NetSurf fork with a macos9 frontend. Carbon UI, QuickDraw plotters, Open Transport networking, Duktape JS engine.
proxy/	Go (stdlib only)	TLS-stripping HTTP proxy. Mac sends plain HTTP, proxy fetches via HTTPS, returns plain HTTP. Deploy on a VPS or run locally.
macSSL sibling repo	C (CW8)	Native TLS 1.2 library for OS 9 — modern HTTPS straight from the Mac, no proxy required. Built on BearSSL with ten embedded root CAs.

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What works today

Rendering pipeline Full NetSurf fetch → parse → cascade → layout → plot Native libcss with var() resolution QuickDraw plotters with offscreen GWorld back-buffer CSS — ~150 properties consumed in layout Custom properties & var() Flex (justify-content, align-content, order) Grid V1 + grid-template-columns/rows, gap border-radius, box-shadow, opacity Linear & radial gradients text-shadow, text-overflow: ellipsis transform (rotate / translate / scale) z-index stacking contexts (CSS 2.1 painting order) CSS counters, viewport units, aspect-ratio Font-family aliases (sans / serif / monospace) Full CSS status →

JavaScript — Duktape 2.7.0 ES5 Closures, prototypes, regex, JSON Promises (polyfill), recursion, Mandelbrot ~6 sec ackermann(3,7) on a 233 MHz G3 Images — all five formats PNG with real per-pixel alpha (lodepng + CopyMask) GIF with palette transparency JPEG, BMP, TIFF Networking Open Transport TCP, plain non-InContext calls HTTP/1.1 + chunked + keep-alive + 3xx follow Connection pooling, 15s no-progress timeout HTTPS via Go proxy or native macSSL Chrome Address bar, back / forward / reload / home Status bar, page-info, multi-window Smooth scroll bar, keyboard scrolling

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Download

Two StuffIt archives in builds/ — pick what you need:

• builds/MacSurf.sit — ready-to-run binary. Expand on Mac OS 9.1+ with CarbonLib 1.5+ and launch.
• builds/MacSurf-BuildPack.sit — full source + CodeWarrior 8 project file. Expand, open MacSurf.mcp in CodeWarrior, choose Build.

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Getting started

Building the browser MacSurf is built on Mac OS 9 with CodeWarrior 8 Pro (8.3 update). Source is cross-compile-clean against Retro68 PowerPC GCC for fast Linux-side syntax checks. Mac-side build guide Linux cross-dev workflow

Running the proxy A single Go binary. No config files. No dependencies beyond stdlib. cd proxy go build -o macsurf-proxy ./macsurf-proxy Deploy guide

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Documentation

• Architecture — rendering modes, proxy services, milestone plan
• Project status — what works, what's next
• Version history — milestone timeline
• CSS status — feature-by-feature CSS coverage
• The MacSurf story — narrative writeup
• Full doc index

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Technical constraints

The platform sets the rules. MacSurf works around them, not against them.

• Cooperative multitasking only. No preemptive threads anywhere. WaitNextEvent drives the UI; Open Transport synchronous calls yield via the Thread Manager on kOTSyncIdleEvent.
• Strict C89. No inline, no //, no designated initializers, no variadic macros, no for-scope declarations. CW8 doesn't compile anything more modern.
• No HTTPS in the browser (without macSSL). All TLS is handled by the proxy — the Mac speaks plain HTTP and the proxy bridges out to HTTPS.
• 16 MB Carbon application partition. libcss allocates from the OS heap and runs out below ~12 MB on real pages.
• Two memory floors: 64 MB RAM (development) on a G3 iMac, 256 MB+ (enthusiast tier) on G4 hardware.

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Prior art

There was nothing here before. The netsurf-dev list has a single 2017 "Port to OS9?" thread with no follow-through. Best references the project was built against:

• Classilla — the Mozilla-era reference Carbon browser. MacSurf borrows the 'carb' resource pattern and Open Transport architecture from Classilla's macsockotpt.c.
• cy384/ssheven — production SSH client for OS 9; the canonical reference for cooperative-multitasking + Open Transport on real hardware.
• cy384/miscellany — the shortest known-good OT HTTP client (~220 lines).

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License

MacSurf is a derivative work of NetSurf and inherits its licensing terms: GPLv2 with the OpenSSL linking exception, plus MIT for visual artwork. The complete text is in LICENSE.

The Go proxy and macSSL ship under permissive licences — see each subproject for details.

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_{Built with stubbornness for a 25-year-old operating system.}