Pale Moon

Pale Moon is a free and open-source web browser licensed under the MPL-2.0 with a stated emphasis on customization. There are official releases for Microsoft Windows, FreeBSD, macOS, and Linux. Pale Moon originated as a fork of Firefox, but has subsequently diverged. The main differences are its user interface, add-on system, and single-process architecture. Pale Moon retains the user interface of Firefox from versions 4 to 28 and supports both legacy Firefox extensions and NPAPI plugins.