Microsoft Puts Slack in Cross Hairs With New Office Chat App - The New York Times

Also see Microsoft launches Teams, takes on Slack on its home turf (Ars Technica)

"Microsoft began working on Microsoft Teams about 18 months ago, after Mr. Gates encouraged Brian MacDonald, a respected Microsoft engineer credited with creating Outlook, the company’s flagship email application, to come up with a new take on productivity applications.

“We’d have pretty frequent conversations, sometimes group reviews, sometimes one-on-ones,” Mr. MacDonald said. “He’d send me big, long memos to consume. I’d send him a few ideas back. It was great.”

Microsoft does not always build a new product when it wants to expand the range of Office. About four years ago, it paid $1.2 billion to acquire Yammer, a social networking app that had found a following in the tech industry. So did Microsoft consider buying Slack?

“It’s not something that I looked at,” Mr. Nadella said, adding that he did not know if others who work for him seriously considered it."

Microsoft Puts Slack in Cross Hairs With New Office Chat App - The New York Times