In 1988 Dan Patterson and Mark Leveson created the improv game show Whose Line Is It Anyway? It was a Hat Trick production for Channel Four, and aired for eleven years.
But it originally began life as a Radio 4 show.
Towards the end of its UK run, the show crossed the Atlantic, taking with it some of its regular North American stars, and was hosted by Drew Carey. It looked and felt a lot like the original.
ABC stopped airing the show in 2007, but it reappeared recently in 2013, with new host Aisha Tylor on The CW network. It featured many of the same performers.
There was an Australian version of the show in 2016, that ran for ten episodes.
Here’s the Israeli version, which aired for two seasons at the start of the millenium. And then was revived in 2006 for two more.
And here’s the Egyptian version that started in 2018.
The Dutch have a slightly different take on the format, called De Lama’s.
In Denmark’s Hatten Rundt, the emphasis is more on proper acting than on comedy, apparently.
Finally, here’s the German version Frei Schnauze.