Installation and compatibility
Firefox add-on technology is modernizing, and traditional add-ons like Mozilla Archive Format will stop working soon. The announced cut-off date is November 14, 2017.
See the add-on documentation for an overview of the recommended alternatives.
You can still install the Mozilla Archive Format add-on on the latest versions of Firefox, SeaMonkey, and Firefox Extended Support Release (ESR) from the Firefox Add-ons website. When this add-on is installed in Firefox, however, performance may be reduced because the optimized multi-process mode of the browser will be disabled.
The most recent version of the add-on is not expected to be compatible with older versions of the browser or with pre-release channels such as Nightly and Beta.
License and previous versions
The Mozilla Archive Format add-on has been created by Christopher Ottley and developed by Paolo Amadini. The latest version of the add-on is available under an MPL 1.1+, GPL 2.0+, LGPL 2.1+ disjunctive tri-license. Previous versions of the add-on and individual source files may be available under different Open Source licenses. The changelog for all the old versions is also available.