Why doesn't Microsoft buy out Firefox browser from Mozilla?

They don't need to buy it. Firefox is free software (as in free speech, and as in free beer). They can take the source code for free, improve it, rebrand it and distribute it. There is one catch; they would have to let others do the same with that product as it must stay free (libre) software. But Microsoft is not in that business. read more

Microsoft is known for providing platform to others rather than buying something and use it as one of their leading components. They can and surely will provide us with a better version of Internet Explorer in future instead of buying Firefox. read more