What popular operating system are the Mac OS X series based on?

More Questions:

What does the "Big Mac Index" measure?

Who was the Phillips screw design named after?

The US Army's elite 101st Airborne Division is known as the "Screaming" what?

What hero of Wagner's "Ring" opera cycle slays the dragon Fafner?

Who was the only woman to hold the title office in the "Book of Judges"?

What snack gave Mickey Mouse his first spoken words?

US city Milwaukee is located on the shores of what lake?

What river flows along the western border of Illinois?

How many flat faces does a dodecahedron have?

The anti-depressant drug Fluoxetine is generally known by what other name?

What kind of gem is El Corazon which is "romanced" in the movie "Romancing the Stone"?

Julia Roberts and Hugh Grant were paired in what romantic comedy?

Which two TV series from the 1980s featured a character named Uncle Jesse?

Audrey Hepburn was born in which country?

What continent is Sao Tome and Principe located in?