Public record
Software health reportschema 0.34.0 · metrics 2.10.0 · 2026-10-24 01:19 UTC

servo / stylo

CSS engine that powers Servo and Firefox

RustNo license detected★ 343 stars⑂ 127 forkssince Feb 2024View on GitHub ↗

servo/stylo holds a health index of 88 out of 100, placing it in the Excellent band. It scores highest on Vitality (100/100) and lowest on Security (48/100). It was last updated 1 day ago. 8 contributors account for most of its recent work.

88
overall / 100
Excellent

Software health index

Metrics are grouped into weighted categories on one standardized 1–100 scale. Overall starts as their weighted mean, calibrated against the distribution of the public record so bands carry percentile meaning; when public evidence triggers the High-Risk Jurisdiction Policy, the rating is adjusted and receives an At Risk ceiling of 34.

88
Exceptional93-100The record's top tier (≈ top 5%); essentially all checked criteria met
Excellent80-92Strong across the board; minor gaps
Good65-79Healthy; gaps are limited and manageable
Moderate50-64Acceptable with notable gaps; review recommended
Weak35-49Material weaknesses across several areas
At Risk20-34Significant weaknesses; adoption warrants caution
Critical1-19Severe problems (abandoned, single-maintainer, no hygiene)
VitalityCommunity &AdoptionSustainability &GovernanceEngineeringQualitySecurityAI Readiness

Score profile

Each axis is a category. The shape matters more than the average — a healthy subject fills the whole shape, while a spike-and-crater profile means strength in one dimension is masking risk in another.

The weighted overall 74 is calibrated to 88 on the published index scale (record calibration 2026-08-02).

Ownership

ServoOrganization · verified domain
1,307 followers193 public repossince Oct 2012

This repository is backed by an organization — shared, accountable stewardship that can outlive any single maintainer.

Package ecosystems

RegistryPackageVersionDownloads / moVersionsLast publishTags
crates.iostylo0.22.066,2212523 days ago—
crates.ioto_shmem0.6.067,950723 days ago—
crates.ioselectors0.41.010,949,6456323 days agocssselectors
crates.ioservo_arc0.5.010,259,858823 days ago—
crates.iostylo_dom0.22.067,7472323 days agocssstyle
crates.iostylo_atoms0.22.067,7362323 days ago—
crates.iostylo_derive0.22.066,3812323 days ago—
crates.iostylo_traits0.22.067,7632323 days ago—

Metrics by category

Vitality

Is the project alive — is code being written and are releases shipping?

100Exceptional · 21% of overall

Development activity

100Exceptional
How it's scored
36/36Push recency — last push 1 days ago
36/36Commit cadence — 52/52 weeks with commits
18/18Commit volume — 1,235 commits in the last year
10/10OpenSSF Scorecard: Maintained — 30 commit(s) and 18 issue activity found in the last 90 days -- score normalized to 10
Inputs used
commits_last_year1,235
human_commit_share1
days_since_last_push1
active_weeks_last_year52

Release discipline

100Exceptional
How it's scored
27/27Ships releases — 21 releases published
36/36Release recency — latest release 23 days ago
27/27Release cadence — a release every ~23.1 days
0/10OpenSSF Scorecard: Signed-Releases — no data
Inputs used
releases_count21
latest_release_tagv0.22.0
releases_from_tagsno
days_since_latest_release23
mean_days_between_releases23.1
Excluded from scoring (no data or not applicable): OpenSSF Scorecard: Signed-Releases. Remaining weights renormalized.

Community & Adoption

Does the project have users, downloads, attention, and a welcoming setup for contributors?

59Moderate · 17% of overall
How it's scored
41.1/60Stars — 343 stars
17.5/25Forks — 127 forks
5/15Watchers — 9 watchers
Inputs used
forks127
stars343
watchers9
growth_stateunverified
growth_factor_pct100
growth_unverified_reasonno_history
How it's scored
22.5/22.5README
0/22.5License — no license file detected
0/18CONTRIBUTING guide
0/13.5Code of conduct
0/7.2Issue template
0/6.3PR template
Inputs used
has_readmeyes
has_licenseno
readme_badges13
has_contributingno
has_issue_templateno
has_code_of_conductno
readme_badge_servicesgithub.com, shields.io
has_pull_request_templateno
How it's scored
80/80Monthly downloads — 21,613,301 downloads/month across crates
0/20Registry dependents — not reported by this ecosystem
Inputs used
packagesstylo, to_shmem, selectors, servo_arc, stylo_dom, stylo_atoms, stylo_derive, stylo_traits
dependents—
ecosystemscrates
total_downloads179,796,004
monthly_downloads21,613,301
unverified_packages_excluded—
Excluded from scoring (no data or not applicable): Registry dependents. Remaining weights renormalized.

Sustainability & Governance

Will the project survive its people — bus factor, responsiveness, who backs it, and package upkeep?

91Excellent · 23% of overall
How it's scored
54/54Bus factor — 8 contributor(s) cover half of all commits
16.4/22.5Commit distribution — top contributor authored 27% of commits
13.5/13.5Contributor breadth — 100 contributors
10/10OpenSSF Scorecard: Contributors — project has 47 contributing companies or organizations
Inputs used
bus_factor8
contributors_sampled100
top_contributor_share0.27
How it's scored
29.8/42Issue resolution — 71% of issues closed
24.9/30PR acceptance — 311/374 decided PRs merged
0/13Newcomer PR acceptance — no first-time contributor's PR decided in 30d
9/15OpenSSF Scorecard: Code-Review — Found 19/29 approved changesets -- score normalized to 6
Inputs used
merged_prs311
open_issues29
closed_issues71
prs_merged_7d5
prs_decided_7d6
prs_merged_30d19
prs_decided_30d25
issue_closed_ratio0.71
closed_unmerged_prs63
first_time_authors_30d0
first_time_prs_merged_30d0
first_time_prs_decided_30d0
Excluded from scoring (no data or not applicable): Newcomer PR acceptance. Remaining weights renormalized.
How it's scored
30/30Ownership backing — organization-owned
20/20Verified domain
22.4/25Owner reach — 1,307 followers of servo
25/25Track record — 193 public repos, account ~14 yr old
Inputs used
followers1,307
owner_typeOrganization
is_verifiedyes
owner_loginservo
public_repos193
account_age_days5,121

Package maintenance

100Exceptional
How it's scored
25/25Published & resolvable — 8 package(s) on crates
35/35Publish recency — latest publish 23 days ago
20/20Version history — 63 published versions
20/20Not deprecated — active, not deprecated or yanked
Inputs used
packagesstylo, to_shmem, selectors, servo_arc, stylo_dom, stylo_atoms, stylo_derive, stylo_traits
ecosystemscrates
any_deprecatedno
min_days_since_publish23

Engineering Quality

Are baseline engineering and documentation practices in place?

62Moderate · 19% of overall
How it's scored
24/24CI workflows — 3 workflow(s)
0/24Tests present
16/16Linter config — rustfmt.toml
0/9.6Pre-commit hooks
0/6.4.editorconfig
20/20OpenSSF Scorecard: CI-Tests — 14 out of 14 merged PRs checked by a CI test -- score normalized to 10
Inputs used
has_ciyes
has_testsno
has_editorconfigno
has_linter_configyes
has_precommit_configno
How it's scored
30/30README
0/25Documentation directory
15/15Documentation / homepage site — https://docs.rs/selectors/
10/10Repository description
0/10Topics
10/10Wiki
Inputs used
topics—
has_wikiyes
homepage—
docs_sitehttps://docs.rs/selectors/
has_readmeyes
has_docs_dirno
has_descriptionyes

Security

Are visible security and supply-chain practices strong, without unresolved high-risk jurisdiction exposure?

48Weak · 16% of overall
How it's scored
6/7.5Binary-Artifacts — binaries present in source code
0/7.5Branch-Protection — no data
2.5/2.5CI-Tests — 14 out of 14 merged PRs checked by a CI test -- score normalized to 10
0/2.5CII-Best-Practices — no effort to earn an OpenSSF best practices badge detected
4.5/7.5Code-Review — Found 19/29 approved changesets -- score normalized to 6
2.5/2.5Contributors — project has 47 contributing companies or organizations
10/10Dangerous-Workflow — no dangerous workflow patterns detected
0/7.5Dependency-Update-Tool — no update tool detected
0/5Fuzzing — project is not fuzzed
0/2.5License — license file not detected
7.5/7.5Maintained — 30 commit(s) and 18 issue activity found in the last 90 days -- score normalized to 10
0/5Packaging — no data
0/5Pinned-Dependencies — dependency not pinned by hash detected -- score normalized to 0
0/5SAST — SAST tool is not run on all commits -- score normalized to 0
0/5Security-Policy — security policy file not detected
0/7.5Signed-Releases — no data
0/7.5Token-Permissions — detected GitHub workflow tokens with excessive permissions
7.5/7.5Vulnerabilities — 0 existing vulnerabilities detected
Inputs used
sourceopenssf_scorecard
checks_evaluated15
scorecard_versionv5.5.0
checks_inconclusive3
scorecard_aggregate4.8
Excluded from scoring (no data or not applicable): Branch-Protection, Packaging, Signed-Releases. Remaining weights renormalized.

AI Readiness

How well is the repo equipped to be developed and maintained with AI coding agents? Carries a deliberately small weight (4%): agent tooling is a real maintenance signal, but a repository with none can still reach 100/100.

52Moderate · 4% of overall
How it's scored
0/45Agent instructions — no CLAUDE.md / AGENTS.md / editor rules
0/15Machine-readable docs (llms.txt)
40/40Legible commit history — 94 of 100 human commits state their intent (structured subject or explanatory body)
Inputs used
has_llms_txtno
llms_txt_url—
legible_history_share0.94
agent_instruction_files—
agent_instruction_max_bytes—
How it's scored
12.6/18One-command bootstrap — Cargo.toml, malloc_size_of/Cargo.toml, selectors/Cargo.toml (toolchain convention, no task runner)
0/22Automated tests
11/11Lint / format config — rustfmt.toml
11/11Static type checking — Rust (statically typed)
10/10Reproducible environment — Nix
0/10Demonstrated agent practice — no agent-authored commits among the last 100
0/8Automated maintenance — no automated dependency updates observed
0/10OpenSSF Scorecard: Pinned-Dependencies — dependency not pinned by hash detected -- score normalized to 0
Inputs used
has_nixyes
has_testsno
lockfiles—
has_dockerfileno
typed_languageyes
bootstrap_files—
has_devcontainerno
has_linter_configyes
typecheck_configs—
agent_commit_share0
toolchain_manifestsCargo.toml, malloc_size_of/Cargo.toml, selectors/Cargo.toml, servo_arc/Cargo.toml, style/Cargo.toml, style_derive/Cargo.toml, style_traits/Cargo.toml, stylo_atoms/Cargo.toml, stylo_dom/Cargo.toml, stylo_static_prefs/Cargo.toml, to_shmem/Cargo.toml, to_shmem_derive/Cargo.toml
dependency_bot_commit_share0
How it's scored
45/45Type-checkable code — Rust (statically typed)
52.2/55Manageable file sizes — 18/349 source files over 60KB
Inputs used
primary_languageRust
largest_source_bytes190,483
source_files_sampled349
oversized_source_files18

Key facts

343GitHub stars
100contributors
1,235commits, last 12 months
1days since last push
21releases
8bus factor
29open issues
crates.iopackage ecosystems

Data collection warnings

  • Star history unavailable: GitHub GraphQL error: Resource not accessible by personal access token
  • No resolved dependencies carried a version and a supported ecosystem

More detail

Star and fork history 0 ★ / 127 ⇿
0Stars
127Forks
21Releases

When each star and fork was added, collected from GitHub and bucketed by day. Cumulative growth sits directly above the daily additions it is made of, so the two read against each other: steady organic accretion looks nothing like an abrupt, short-lived burst. Where that difference is measurable, it is reported as growth authenticity.

025507510012512132024-032025-062026-10
Major 0Minor 21Patch 0

Each point covers 3 days.

OpenSSF Scorecard 4.8 / 10
4.8aggregate

Independent, tool-agnostic security assessment from the open-source OpenSSF Scorecard. Each check rewards a security practice, not a specific vendor's tool. Checks Scorecard could not determine are marked n/a and excluded from the security score (never counted as zero).Scorecard v5.5.0 · 2026-10-24 01:19 UTC

8Binary-Artifactsbinaries present in source code
n/aBranch-Protectioninternal error: error during branchesHandler.setup: internal error: some github tokens can't read classic branch protection rules: https://github.com/ossf/scorecard-action/blob/main/docs/authentication/fine-grained-auth-token.md
10CI-Tests14 out of 14 merged PRs checked by a CI test -- score normalized to 10
0CII-Best-Practicesno effort to earn an OpenSSF best practices badge detected
6Code-ReviewFound 19/29 approved changesets -- score normalized to 6
10Contributorsproject has 47 contributing companies or organizations
10Dangerous-Workflowno dangerous workflow patterns detected
0Dependency-Update-Toolno update tool detected
0Fuzzingproject is not fuzzed
0Licenselicense file not detected
10Maintained30 commit(s) and 18 issue activity found in the last 90 days -- score normalized to 10
n/aPackagingpackaging workflow not detected
0Pinned-Dependenciesdependency not pinned by hash detected -- score normalized to 0
0SASTSAST tool is not run on all commits -- score normalized to 0
0Security-Policysecurity policy file not detected
n/aSigned-Releasesno releases found
0Token-Permissionsdetected GitHub workflow tokens with excessive permissions
10Vulnerabilities0 existing vulnerabilities detected
Direct dependencies 111
RegistryPackageVersion constraintManifest
crates.ioapp_units0.7malloc_size_of/Cargo.toml
crates.iocssparser0.38malloc_size_of/Cargo.toml
crates.ioeuclid0.22malloc_size_of/Cargo.toml
crates.iohashbrown0.17malloc_size_of/Cargo.toml
crates.ioparking_lot0.12malloc_size_of/Cargo.toml
crates.ioselectors—malloc_size_of/Cargo.toml
crates.ioservo_arc—malloc_size_of/Cargo.toml
crates.iosmallbitvec2.3.0malloc_size_of/Cargo.toml
crates.iosmallvec1.13malloc_size_of/Cargo.toml
crates.iostring_cache0.11malloc_size_of/Cargo.toml
crates.iothin-vec0.2.13malloc_size_of/Cargo.toml
crates.iovoid1.0.2malloc_size_of/Cargo.toml
crates.iobitflags2selectors/Cargo.toml
crates.iocssparser0.38selectors/Cargo.toml
crates.ioderive_more2selectors/Cargo.toml
crates.iohashbrown0.17selectors/Cargo.toml
crates.iorustc-hash2.1.1selectors/Cargo.toml
crates.iolog0.4selectors/Cargo.toml
crates.ioprecomputed-hash0.1selectors/Cargo.toml
crates.ioservo_arc—selectors/Cargo.toml
crates.iosmallvec1.0selectors/Cargo.toml
crates.ioto_shmem—selectors/Cargo.toml
crates.ioto_shmem_derive—selectors/Cargo.toml
crates.ionew_debug_unreachable1selectors/Cargo.toml
crates.ioserde1.0servo_arc/Cargo.toml
crates.iostable_deref_trait1.0.0servo_arc/Cargo.toml
crates.ioapp_units0.7.8style/Cargo.toml
crates.ioarrayvec0.7style/Cargo.toml
crates.ioatomic_refcell0.1style/Cargo.toml
crates.iobitflags2style/Cargo.toml
crates.iobyteorder1.0style/Cargo.toml
crates.iocssparser0.38style/Cargo.toml
crates.ioderive_more2style/Cargo.toml
crates.iodom—style/Cargo.toml
crates.ionew_debug_unreachable1.0style/Cargo.toml
crates.ioencoding_rs0.8style/Cargo.toml
crates.ioeuclid0.22style/Cargo.toml
crates.iorustc-hash2.1.1style/Cargo.toml
crates.iohashbrown0.17style/Cargo.toml
crates.ioicu_segmenter>= 1.5, <= 2.*style/Cargo.toml
crates.ioindexmap2style/Cargo.toml
crates.ioitertools0.14style/Cargo.toml
crates.ioitoa1.0style/Cargo.toml
crates.iolog0.4style/Cargo.toml
crates.iomalloc_size_of—style/Cargo.toml
crates.iomalloc_size_of_derive0.1style/Cargo.toml
crates.iomozbuild0.1style/Cargo.toml
crates.ioweb_atoms0.3.0style/Cargo.toml
crates.iomime0.3.13style/Cargo.toml
crates.ionum_cpus1.1.0style/Cargo.toml
crates.ionum-integer0.1style/Cargo.toml
crates.ionum-traits0.2style/Cargo.toml
crates.ionum-derive0.4style/Cargo.toml
crates.ioparking_lot0.12style/Cargo.toml
crates.ioprecomputed-hash0.1.1style/Cargo.toml
crates.iorand0.8.6style/Cargo.toml
crates.iorayon1style/Cargo.toml
crates.iorayon-core1style/Cargo.toml
crates.ioselectors—style/Cargo.toml
crates.ioserde1.0style/Cargo.toml
crates.ioservo_arc—style/Cargo.toml
crates.iostylo_atoms—style/Cargo.toml
crates.iosmallbitvec2.3.0style/Cargo.toml
crates.iosmallvec1.0style/Cargo.toml
crates.iostatic_assertions1.1style/Cargo.toml
crates.iostatic_prefs—style/Cargo.toml
crates.iostring_cache0.11style/Cargo.toml
crates.iostrum0.28style/Cargo.toml
crates.iostrum_macros0.28style/Cargo.toml
crates.iostyle_derive—style/Cargo.toml
crates.iostyle_traits—style/Cargo.toml
crates.ioto_shmem—style/Cargo.toml
crates.ioto_shmem_derive—style/Cargo.toml
crates.iothin-vec0.2.1style/Cargo.toml
crates.iouluru3.0style/Cargo.toml
crates.iovoid1.0.2style/Cargo.toml
crates.iourl2.5style/Cargo.toml
crates.iodarling0.20style_derive/Cargo.toml
crates.ioproc-macro21style_derive/Cargo.toml
crates.ioquote1style_derive/Cargo.toml
crates.iosyn2style_derive/Cargo.toml
crates.iosynstructure0.13style_derive/Cargo.toml
crates.ioapp_units0.7style_traits/Cargo.toml
crates.iobitflags2style_traits/Cargo.toml
crates.iocssparser0.38style_traits/Cargo.toml
crates.ioeuclid0.22style_traits/Cargo.toml
crates.iomalloc_size_of—style_traits/Cargo.toml
crates.iomalloc_size_of_derive0.1style_traits/Cargo.toml
crates.ioselectors—style_traits/Cargo.toml
crates.ioserde1.0style_traits/Cargo.toml
crates.ioservo_arc—style_traits/Cargo.toml
crates.iostylo_atoms—style_traits/Cargo.toml
crates.iothin-vec0.2style_traits/Cargo.toml
crates.ioto_shmem—style_traits/Cargo.toml
crates.ioto_shmem_derive—style_traits/Cargo.toml
crates.iourl2.5style_traits/Cargo.toml
crates.iostring_cache0.11stylo_atoms/Cargo.toml
crates.iobitflags2stylo_dom/Cargo.toml
crates.iomalloc_size_of—stylo_dom/Cargo.toml
crates.iocssparser0.38to_shmem/Cargo.toml
crates.iohashbrown0.17to_shmem/Cargo.toml
crates.ioservo_arc—to_shmem/Cargo.toml
crates.iosmallbitvec2.3.0to_shmem/Cargo.toml
crates.iosmallvec1.13to_shmem/Cargo.toml
crates.iostring_cache0.11to_shmem/Cargo.toml
crates.iothin-vec0.2.1to_shmem/Cargo.toml
crates.iodarling0.20to_shmem_derive/Cargo.toml
crates.ioproc-macro21to_shmem_derive/Cargo.toml
crates.ioquote1to_shmem_derive/Cargo.toml
crates.iosyn2to_shmem_derive/Cargo.toml
crates.iosynstructure0.13to_shmem_derive/Cargo.toml
All dependencies 52

Full resolved dependency set from the GitHub dependency graph: 47 direct and 5 indirect (transitive) packages. The transitive closure is complete when the repository commits a lockfile.

RegistryPackageVersionRelation
crates.ioapp_units—direct
crates.ioarrayvec—direct
crates.ioatomic_refcell—direct
crates.iobitflags—direct
crates.iobyteorder—direct
crates.iocssparser—direct
crates.iodarling—direct
crates.ioderive_more—direct
crates.ioencoding_rs—direct
crates.ioeuclid—direct
crates.iohashbrown—direct
crates.ioicu_segmenter—direct
crates.ioindexmap—direct
crates.ioitertools—direct
crates.ioitoa—direct
crates.iolog—direct
crates.iomalloc_size_of_derive—direct
crates.iomime—direct
crates.iomozbuild—direct
crates.ionew_debug_unreachable—direct
crates.ionum-derive—direct
crates.ionum-integer—direct
crates.ionum-traits—direct
crates.ionum_cpus—direct
crates.ioparking_lot—direct
crates.ioprecomputed-hash—direct
crates.ioproc-macro2—direct
crates.ioquote—direct
crates.iorand—direct
crates.iorayon—direct
crates.iorayon-core—direct
crates.iorustc-hash—direct
crates.ioserde—direct
crates.iosmallbitvec—direct
crates.iosmallvec—direct
crates.iostable_deref_trait—direct
crates.iostatic_assertions—direct
crates.iostring_cache—direct
crates.iostrum—direct
crates.iostrum_macros—direct
crates.iosyn—direct
crates.iosynstructure—direct
crates.iothin-vec—direct
crates.iouluru—direct
crates.iourl—direct
crates.iovoid—direct
crates.ioweb_atoms—direct
crates.iobindgen—indirect
crates.ioregex—indirect
crates.iostring_cache_codegen—indirect
crates.iotoml—indirect
crates.iowalkdir—indirect
Dependency advisories not assessed

Advisory matching could not run for this report: No resolved dependencies carried a version and a supported ecosystem

Raw JSON report machine-readable

Feedback

Spotted something off in this report, or have thoughts to share? Wrong measurements, missed tooling, ideas, questions — anything is welcome. Every message is read and gets a response.

The message is kept through sign-in.

Scores are signals, not warranties. They reflect publicly visible practices on GitHub — not a code audit, and not a security guarantee.

Missing data is excluded and weights renormalized, never scored as zero. Methodology is versioned and open: metrics v2.10.0, schema v0.34.0 — full methodology · metrics wiki.

How one result sits in the wider record: aggregate statistics — crates.io.