Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, Mozilla Corporation. Firefox is officially available for Windows 7 or newer, macOS and Linux; its unofficial ports are available for various Unix and Unix-like operating systems including FreeBSD, OpenBSD, NetBSD, illumos and Solaris Unix. Developer(s): Mozilla Foundation and its contributors, Mozilla Corporation Initial release: 23, 2002 Written in: C++, JavaScript, HTML, C, Rust