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Safari is macOS/iOS only.

WebKit, the enginge for Safari, is not. Epiphany uses the same engine and is available for Linux. I'm sure there's a Windows WebKit browser as well.

Qt has a WebKit thingy so you can build a WebKit browser across platforms even in Python:

They are pushing the Blink engine now instead, though...

Funnily enough, the PlayStation line uses WebKit as the engine for its web browser