The fiddler landing page says it runs on Windows, macOS, and Linux, so maybe give it another try.

The original thing is now called Fiddler Classic and it is still Windows only. Not maintained anymore, sadly. It has first class scripting support.

	▲	leptons a day ago \| parent [-]
		I still use Fiddler Classic, at least once a week when I need to dig-in on a problem. It occasionally gets an update though I can't remember the last time it did. It's so powerful, especially with the JScript scripting language. Such a powerful tool.