What AI does
AI analyzes tasks, changes code, adds tests, runs checks, and investigates failures. The work continues across modules.
AI-autonomous software engineering experiment
Can AI build and maintain
a browser?
ZeroWeb tests whether AI can sustain a large systems project. One human designs, decides and verifies; AI develops the Rust browser and its product code, with almost no code written by hand.
Experimental · Not ready for everyday browsing or production use
Code commits15,100+developed autonomously by AI · one human: design, decisions, verification
full WPT pass rate78.85%1,789,714 / 2,269,629 upstream subtests passing, measured against the entire WPT corpus · see the data →
The experiment
The browser is the test case.
A browser is large enough to test more than code generation. It requires long-term architecture work, standards implementation, debugging, security boundaries, graphics, and cross-platform integration. Verification runs throughout.
How the work is constrained
Specifications, module boundaries, review rules, CI, WPT, reftests, and browser comparisons decide whether a change is acceptable.
What counts as progress
A larger repository is not the goal. Features must compile, run, and pass the checks appropriate to the behavior being changed.
- Test subject
- A cross-platform browser
- Implementation
- Browser core and product code in Rust
- Validation
- Builds, tests, WPT and browser comparisons
The result is judged by working software and reproducible checks, not generated line count.
Runnable code
Two entrypoints into the same project.
01
ZeroBrowser
The desktop entrypoint used to integrate and test the browser subsystems. It is not yet an everyday browser.
View browser application02
ZeroWebView
A Rust API for embedding the page pipeline in host applications. The API and compatibility surface are still evolving.
View WebView libraryImplementation scope
From request to rendered output.
The repository separates the systems that load, parse, lay out, and render a page so each part can be implemented and verified independently.
- 01NetworkResources & navigation
- 02DOM + CSSDocument & rules
- 03StyleCascade & computed values
- 04LayoutGeometry & flow
- 05RenderPaint & composite
Engineering method
AI output is checked like engineering work.
Browser code in Rust
The browser core, host layers, and product code are written in Rust. External crates provide bounded low-level capabilities.
Standards-driven
Web behavior is verified against WPT, CSSWG reftests, and browser comparisons.
Checks are required
Formatting, static analysis, unit tests, integration tests, and platform CI guard the repository.
Progress has sources
Updates link to commits and roadmap items so the experiment can be inspected rather than taken on trust.
Current status
Useful as an experiment, incomplete as a browser.
Core subsystems and runnable entrypoints exist. Real-site compatibility, complete DOM and Web APIs, and everyday browser behavior remain active work.
See the detailed roadmapImplemented foundationsDOM, CSS, style, layout, rendering, network and security basics
In progressBrowser shell, rendering compatibility, DOM and Web API coverage
Not yet completeWebGL / WebGPU, SVG documents, animation fidelity and real-site behavior
Run the code
Start with a local build.
The repository includes a desktop browser entrypoint and a smaller WebView rendering demo. Platform prerequisites are documented in the README.
ZeroBrowser
Launch the desktop browser entrypoint.
$ make browserWebView demo
Run the smallest rendering pipeline demo.
$ cargo run --bin webview-demoThese commands build experimental software; see the README for platform prerequisites and V8 setup.
Read the setup guide →Project journal
Progress, with sources.
A running record of what changed, what is still in motion, and where each update comes from.
Twelve goals closed in one week; full-WPT pass rate reaches 68.36%
Seven of the twelve closed goals were chartered during the same week, and webcrypto-compat-v3 went from charter to archive in two days. The full-WPT pass rate rose from 42.11% to 68.36%. Rendering failures fell from 757 to 691.
Read update →CSS testharness corpus chartered and closed in three days; rendering failures down to 757
Six goals closed with final numbers, including css-testharness-compat, chartered on 10-27 and closed on 10-30. As the large encoding and wasm corpus runs were recorded, the full-WPT pass rate rose from 7.41% to 42.11%. Rendering failures fell from 884 to 757.
Read update →Rendering failures fall to 884
33 previously closed goals were archived, and 15 more reached a terminal state. Rendering fixes reduced full-corpus failures from 1,104 to 884; media timing and browser stability also improved.
Read update →Inspect the experiment
Read the code.
Check the evidence.
The repository, development history, tests, roadmap, and weekly updates are public. Contributions are expected to meet the same verification rules.
Engineering guides
How ZeroWeb tests AI-autonomous software engineering
A browser gives AI development a long-running test case: architecture, code, debugging and verification must work together.
ZeroWeb Rust browser architecture: from request to pixels
Follow the page pipeline and the boundaries between the browser application, embeddable WebView, engine and rendering infrastructure.
Getting started with ZeroWebView and ZeroBrowser
Prepare a local checkout, launch the desktop browser and inspect the WebView API before embedding the experimental engine.
How to read ZeroWeb WPT and performance results
Understand self-source reftests, assertion-based suites, changing corpus sizes and p95 benchmarks before comparing results.