Microsoft infamously invested $150 million in archenemy Apple in 1997 as the company was facing bankruptcy right after the return of Steve Jobs, and according to former CEO Steve Ballmer, it was the craziest thing the Windows-maker ever did.

Ballmer spends more of his time on the basketball court now than working on the next big tech ideas, but in an interview with Bloomberg this morning, Ballmer was brought on to talk about the Microsoft’s battle with Amazon. After saying Amazon is not a great place to work, the conversation drifted to Apple and Ballmer actually admitted that “they’ve done a great job.”

Coming from the guy who laughed off the iPhone because he thought the Zune was killer, that’s a hell of a compliment. Watch what Ballmer had to say about Microsoft’s rivalry with Apple below: