Free and open source web browser developed by Mozilla, heir to the Netscape lineage and today the only major browser built on an engine (Gecko) that is not controlled by an advertising company. It popularised tabbed browsing and extensions, and it remains the reference point for an open, standards-driven and user-respecting web.
The Preservation Rating scores how well this entry is archived — not how good the software is. It's calculated automatically from what's already on this page: working mirrors, documentation, a reproducible build, a clearly identified license, and complete metadata. Nothing here is entered by hand; it updates itself whenever the entry changes.
