Firefox 4 is available to download for Windows, Mac OS X and Linux in more than 80 languages. Firefox 4 will also be available on Android and Maemo devices soon.
Firefox 4 is the fastest Firefox yet, between two and six times faster than previous releases.
Firefox supports modern Web technologies, including HTML5.
Security and privacy
- Do Not Track: Firefox is leading the Web towards a universal standard Do Not Track feature that allows users to opt-out of tracking used for behavioral advertising.
- Firefox puts privacy first, fixing flaws in some Web standards to prevent others from accessing your browser history.
- HTTP Strict Transport Security (HSTS): automatically establishes secure connections to stop “man in the middle” attacks and keep sensitive data safe from interception during the log-in process.
- Content Security Policy (CSP): prevent cross-scripting attacks by allowing sites to explicitly tell the browser which content is legitimate.