Firefox Browser

Firefox is the last mainstream browser that is not built on Google's Chromium or Apple's WebKit. That alone is a reason to keep it around. Its Gecko engine is what stops the web becoming a single-vendor monoculture. It is open source, customizable, on every platform, and hardens well with a few changes to its settings. Telemetry is on by default, which makes a pass through the privacy settings worthwhile. Mozilla also leans heavily on a Google search deal for revenue, which raises fair questions about its independence.