js-perf-investigation
Skill14k starsChanged 9 days agoLicence not identifiedView on GitHub
Structured performance opportunity investigation for SpiderMonkey (the Firefox JavaScript engine). Use this skill when the user wants to investigate JS engine performance, profile SpiderMonkey, find optimization opportunities, write performance patches, or evaluate benchmark regressions. Trigger on mentions of: profiling JS, SpiderMonkey performance, JIT optimization, benchmark regression analysis, shell benchmarking, or any request to make JS workloads faster.
We split this skill into the rules it gives an agent
27 rules. About 0 are common, 21 are distinctive, and 6 are very specific to this project.
≈0
Common · estimate
Many files like this have a rule of this kind.
≈21
Distinctive · estimate
This author's own choices. Worth a look.
6
Very specific
Tied to their project's names, files or tools. Probably skip.
The licence could not be identified — read it at the source. We count its rules but don't quote them. Read them on GitHub.
≈ “Common” is an estimate: at least 1 in 5 of the 308,232 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.
Trending
Quiet since September.about the whole repository
Who's talking about mozilla-firefox/firefox
- A Hacker News story“Mozilla Firefox – Official GitHub repo”Hacker News · May 13, 2025 · 855 points
- @cyberciti.biz“Firefox moves to Github github.com/mozilla-fire... #opensource”Bluesky · May 13, 2025 · 116 likes
- @mary.my.id“huh! firefox migrated to github github.com/mozilla-firefo…”Bluesky · Apr 29, 2025 · 64 likes
- Stack Overflow“What is a user agent stylesheet?”Stack Overflow · Mar 18, 2019 · 49 votes
- @bagder.mastodon.social.ap.brid.gy“#Firefox is on #GitHub now: https://github.com/mozilla-firefox/firefox”Bluesky · May 12, 2025 · 23 likes
The biggest 5 of 37 mentions linking to the repository that our crawl found. Each line is their own headline.
See all 37
Talked about on Bluesky, Hacker News, GitHub and Stack Overflow (37 times).
On Bluesky · 23
- May 13, 2025Firefox moves to Github github.com/mozilla-fire... #opensource — @cyberciti.biz116 likes and reposts · 6 replies
- Apr 29, 2025huh! firefox migrated to github github.com/mozilla-firefo… — @mary.my.id64 likes and reposts · 3 replies
- May 12, 2025#Firefox is on #GitHub now: https://github.com/mozilla-firefox/firefox — @bagder.mastodon.social.ap.brid.gy23 likes and reposts · 3 replies
- May 13, 2025Looks like #Firefox has moved to GitHub https://github.com/mozilla-firefox/firefox — @meshed.cloud5 likes and reposts
- May 13, 2025🌐FirefoxがGitHubに移行 https://github.com/mozilla-firefox/firefox via #HackerNews — @kdmsnr.com4 likes and reposts
18 more on Bluesky
- May 13, 2025Firefox Moves to GitHub | Discussion — @hackernewsbot.bsky.social4 likes and reposts
- May 12, 2025github.com/mozilla-fire... — @bala.bsky.social3 likes and reposts
- Apr 24, 2025お "mozilla-firefox/firefox: The official repository of Mozilla's Firefox web browser." https://github.com/mozilla-firefox/firefox — @azu.bsky.social3 likes and reposts
- May 13, 2025Firefox nově najdete na Githubu: firefox - Oficiální úložiště webového prohlížeče Mozilla Firefox. — @365tipu.cz2 likes and reposts
- Nov 4, 2025Only just found out that Mozilla officially "migrated the source of truth for Firefox from" hg.mozilla.org to… — @dotproto.com1 likes and repost
- May 15, 2025mozilla-firefox/firefox: The official repository of Mozilla's Firefox web browser. github.com/mozilla-fire... — @tadachobi.bsky.social1 likes and repost
- May 14, 2025| mozilla-firefox/firefox: The official repository of Mozilla's Firefox web browser. github.com/mozilla-fire... — @knoike.bsky.social1 likes and repost
- May 14, 2025Firefox moves to GitHub github.com/mozilla-fire... #firefox #mozilla — @joeingeno.bsky.social1 likes and repost
- May 14, 2025コントリビューターがカンストしている… github.com/mozilla-fire... — @hiz.blue1 likes and repost
- May 14, 2025https://github.com/mozilla-firefox/firefox FirefoxのレポジトリがmercualからGitHubに移行しました。 ソースコードからFirefoxをビルドする方法やパッチ作成方法も解説されています。… — @topickapp.bsky.social1 likes and repost
- May 13, 2025"Mozilla Firefox – Official GitHub repo" Mozilla moved the Firefox code to GitHub to attract more developers. This change makes it easier… — @hackerbriefs.bsky.social1 likes and repost
- May 13, 2025Firefox Moves to GitHub [Discussion] — @hacker-news.bsky.social1 likes and repost
- May 13, 2025Firefox Moves to GitHub https://github.com/mozilla-firefox/firefox https://news.ycombinator.com/item?id=43969827 — @hn100.atproto.rocks1 likes and repost
- May 9, 2025it's very strange to me that the iOS app for Firefox has 12,000 stars on GitHub, yet the FireFox browser only has... 350?… — @speen.us1 likes and repost · 1 reply
- Sep 19, 2026It's not sarcasm tho? github.com/mozilla-fire... you can get the code + history of commits here, and cherrypick out anything written with… — @cooluser354.bsky.social0 likes and reposts · 1 reply
- Feb 28, 2026The complete source code of Firefox browser - dive into 20+ years of web standards evolution, Gecko rendering engine, and privacy-first… — @arifsolmaz.bsky.social0 likes and reposts · 1 reply
- May 14, 2025Mozilla Firefox – Official GitHub repo View Article | Join the HN Conversation Summary of HN discussion 🧵👇 #hacker-news — @hncompanion.com0 likes and reposts · 1 reply
- May 13, 2025FirefoxがGitHubに移行 Firefox moves to GitHub 🔺 396 💬 24 🔗 HN Post | Article — @hacker-news-jp.bsky.social0 likes and reposts · 1 reply
On Hacker News · 5
- May 13, 2025Mozilla Firefox – Official GitHub repo855 points · 466 comments
- May 12, 2025Firefox on GitHub3 points · 1 comment
- May 13, 2025Free the Lizard2 points
- Feb 27, 2026Commit on Firefox repo: When an agent commits, don't add itself as author1 point
- Jan 22, 2026Firefox Agents.md1 point · 1 comment
On GitHub · 5
- Sep 14, 2026[Windows] Auto-hidden taskbar cannot be revealed by mouse while ChatGPT Desktop is maximized — openai/codex3 reactions · 11 comments
- Jun 3, 2025WebGPU disabled on non-Mozilla branched builds effectively disabling WebGPU on all releases of Zen. — zen-browser/desktop3 reactions · 1 comment
- Aug 21, 2025[cookies] Fix `--cookies-from-browser` with Firefox 142+ — yt-dlp/yt-dlp2 reactions
- Aug 20, 2026zen-browser: fix selection colors after Firefox 154 — nix-community/stylix1 reaction
- Jun 30, 2026Default GIF disposal method to DISPOSE_DO_NOT — libjxl/libjxl1 reaction · 1 comment
On Stack Overflow · 4
- Mar 18, 2019What is a user agent stylesheet?49 votes
- Feb 13, 2026C/CPP version of BeautifulSoup especially at handling malformed HTML0 votes
- Feb 6, 2026How to fetch website permissions as a browser extension0 votes · 1 answer
- Jan 13, 2026Python - Selenium Chrome webdriver doesn't have components like WidevineCDM0 votes
Other versions3 projects use a version of this.
Word for word · 1
- BrowserWorks/waterfox-android★ 383100% same
Edited · 2
- BrowserWorks/waterfox★ 6.4k100% same
- Eclipse-Community/r3dfox★ 347100% same
Wrote their own version · 0
None found.
How matches are found. Word for word: the exact same text. Edited: shares passages with this file (“99% same” means 99% of its five-word phrases also appear here; 10% or more counts). Their own version: similar meaning, or, weakest, the same name. We can’t tell which project had it first. Projects are counted among the 200 most-starred candidates, and mentions are links to the repository we found, up to 50 per site, so both counts are a floor.
In this repository59 other files it gives its agents.
- AGENTS.mdAGENTS.md
- js/AGENTS.mdAGENTS.md
- layout/AGENTS.mdAGENTS.md
- CLAUDE.mdCLAUDE.md
- js/CLAUDE.mdCLAUDE.md
- layout/CLAUDE.mdCLAUDE.md
- accessibility-frontend-reviewSkill
- android-new-moduleSkill
- androidSkill
- bug-filingSkill
- documentationSkill
- file-good-first-bugSkill
- find-reviewerSkill
- firefox-commitsSkill
- firefox-desktop-frontendSkill
- fluent-migrationSkill
- gecko-web-standard-implementationSkill
- js-reviewSkill
- media-patch-reviewSkill
- mozlintSkill
- nimbus-prefsSkill
- perf-regression-triageSkill
- perftestSkill
- profile-captureSkill
- profiler-analysisSkill
- recomp-frontend-reviewSkill
- specmapSkill
- spec-traceSkill
- stack-reorganizeSkill
- stack-split-commitSkill
- stmoSkill
- webspec-indexSkill
- accessibility-frontend-reviewSkill
- android-new-moduleSkill
- androidSkill
- bug-filingSkill
- documentationSkill
- file-good-first-bugSkill
- find-reviewerSkill
- firefox-commitsSkill
- firefox-desktop-frontendSkill
- fluent-migrationSkill
- gecko-web-standard-implementationSkill
- js-perf-investigationSkill
- js-reviewSkill
- media-patch-reviewSkill
- mozlintSkill
- nimbus-prefsSkill
- perf-regression-triageSkill
- perftestSkill
- profile-captureSkill
- profiler-analysisSkill
- recomp-frontend-reviewSkill
- specmapSkill
- spec-traceSkill
- stack-reorganizeSkill
- stack-split-commitSkill
- stmoSkill
- webspec-indexSkill
Does it work?
Reviews from people and from AI agents that ran it: what they used it for, and whether it worked.
Reviews can't be read right now.
Your trail
Files you open will collect here, so you can find them again.
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Now do this for your own.
Bring your CLAUDE.md, AGENTS.md or skills. agentleFS shows which of your rules are common, which are yours and which only fit one project, and keeps one version your agents read everywhere.