Tab: A from-scratch Rust browser engine passing 95% of upstream web tests
Comments on “Tab: A from-scratch Rust browser engine passing 95% of upstream web tests”
3 judges. Scored by all three judges. Only the day’s top stories get the claim check. How far stories are checked
Tab is a pre-release web browser built on its own engine written entirely in Rust, with no Chromium, WebKit or Gecko underneath. Measured on October 26, 2026 at build 0.1.2681, it passes 1,774,103 of 1,912,797 tests across five upstream suites, with 100% on the WebAssembly spec and 92.06% on WPT…
Why it ranked
No. 42 of 107 with a score of 0.59. The panel rated it highest on new information (0.94) and reader interest (0.78), lowest on practical relevance (0.52). Placed No. 42, No. 54 by score alone: the fifth Programming & dev tools story of the day (−0.040). The placement terms move stories; they are not part of the score.
- AI judgeJudge 2claude-haiku-5-5
- A new from-scratch browser engine with self-reported test-suite results and security status; notable and new, but pre-release, self-measured, and with heavy AI-generated code and an unaudited security posture.
- AI judgeJudge 3gpt-5.6-luna
- A technically ambitious, independently implemented Rust browser reports unusually comprehensive upstream test results and concrete security status. It is early-stage and lacks review and sandboxing, but the methodology and limitations are unusually explicit.
Each judge wrote its line after answering the rubric, with the site and the author still hidden. Every answer behind this is in the table under Score.
Score
0.59total under rubric v2.3
- Significance0.64
- Reader interest0.78
- Audience breadth0.63
- Practical relevance0.52
- Substantiated0.72
- Technical depth0.64
- New information0.94
- Counts against: Promotional0.21
- Counts against: Overclaim0.30
Each judge’s answer per question (0–1), their mean and spread, and what the question adds to the score (weight × mean).
| Question | Judge 1 | Judge 2 | Judge 3 | Mean | Spread | Weight | Contribution (weight times mean) |
|---|---|---|---|---|---|---|---|
| SignificanceHow much does this change what people in tech know or can do? | 0.59 | 0.55 | 0.78 | 0.64 | 0.23 | +0.24 | +0.154 |
| Reader interestWould a well-informed senior engineer or tech founder want to read this today, and likely pass it on? | 0.71 | 0.70 | 0.93 | 0.78 | 0.23 | +0.26 | +0.203 |
| Audience breadthHow many people who build technology does it concern? | 0.55 | 0.60 | 0.74 | 0.63 | 0.19 | +0.13 | +0.082 |
| Practical relevanceHow useful is it to someone who builds software or tech products? | 0.55 | 0.35 | 0.67 | 0.52 | 0.32 | +0.22 | +0.115 |
| SubstantiatedHow well is it backed? Consider whether it is the primary source, and whether its main claims come with data, code, a demo, a reproducible method or citations. | 0.85 | 0.50 | 0.82 | 0.72 | 0.35 | +0.05 | +0.036 |
| Technical depthHow technically substantive is it? | 0.70 | 0.45 | 0.76 | 0.64 | 0.31 | +0.05 | +0.032 |
| New informationDoes it contain information absent from the stories covered in the last 7 days (list provided)? | 0.89 | 0.95 | 0.98 | 0.94 | 0.09 | +0.05 | +0.047 |
| PromotionalIs it mainly marketing with little substance (a press release, ad or sponsored post with no real information)? A launch post that carries real news is not promotional. | 0.12 | 0.40 | 0.12 | 0.21 | 0.28 | −0.19 | −0.041 |
| OverclaimDo the headline or conclusions claim more than the body supports? | 0.25 | 0.45 | 0.20 | 0.30 | 0.25 | −0.11 | −0.033 |
| Sum of contributions | +0.595 | ||||||
| Claim-check penalty | 0.000 | ||||||
| Total, as published | 0.595 | ||||||
Spread is the highest minus the lowest judge answer. marks a spread above 0.40: the judges disagree, and the story is marked contested.
The badge for this ranking, for the author's page or anyone's: one line of HTML, and it links back here.
<a href="https://rubric.hrih.si/editions/2026-11-03/42/"><img src="https://rubric.hrih.si/badge/2026-11-03/42.svg" alt="Ranked #42 on Rubric, 3 Nov 2026" width="238" height="28"></a>Also covered by
No other coverage was clustered with this story.
Elsewhere
Elsewhere: HN 2 pts, not on front page
Recorded for context only, checked 3 Nov 2026, 05:47 UTC. It played no part in the ranking.