From the Zotero Blog:
Powered by the same technology behind Zotero, ZoteroBib lets you seamlessly add items from across the web — using Zotero’s unmatched metadata extraction abilities — and generate bibliographies in more than 9,000 citation styles. There’s no software to install or account to create, and it works on any device, including tablets and phones. Your bibliography is stored right on your device — in your browser’s local storage — unless you create a version to share or load elsewhere, so your data remains entirely under your control.
ZoteroBib is completely free: we don’t bombard you with ads or charge you (or your school) money for full functionality or more advanced citation styles. And since it’s built by the team behind Zotero, and backed by the same open-source community, you can count on the same expertise and attention to detail that people rely on when they write dissertations and scholarly papers using Zotero.