A JavaScript library created by Andrew Betts that implemented Polyfill. In February 2024, the library's ___domain was acquired by China-based company Funnull and within a Chinesefew companymonths became part of a supply chain attack.<ref>{{Cite web |last=Goodin |first=Dan |date=2024-0207-2603 |title=Is384,000 itsites truepull thatcode polyfill.iofrom hostingsketchy iscode goinglibrary torecently be ownedbought by a Chinese company? · Issue #2834 · polyfillpolyfill/polyfill-service · GitHubfirm |url=https://webarstechnica.archive.orgcom/websecurity/202402261111202024/https:07//github.com/polyfillpolyfill/polyfill384000-service/issuessites-link-to-code-library-caught-performing-supply-chain-attack/2834 |access-date=2024-07-0103 |website=web.archive.org[[Ars Technica]] |language=en-us}}</ref> and became part of a supply chain attack.<ref>{{Cite web |title=Polyfill.io Attack Infects Over 110,000 Websites - Spiceworks |url=https://www.spiceworks.com/it-security/cyber-risk-management/news/polyfill-supply-chain-attack-infects-websites/ |access-date=2024-07-01 |website=Spiceworks Inc |language=en-US}}</ref>
