Slack users I know, including me, love many things about the service. As the company likes to brag, it's fast, it's transparent, and it's great for brainstorming.

For those still outside the cult of Slack, it's a service - available as a desktop or mobile app, or a website - which is essentially a series of public chat rooms (called channels) on topics relevant to a company or to teams within a company.

Though it has plenty of competitors, Slack claims to be the 'fastest growing business application in history'.

Walt Mossberg Quotes