Slack, a group chat and instant messaging program popular in tech and digital media workplaces, was down for a while this afternoon. Then it was back up for a little bit, but now it is down again. We will update this post when and if Slack commits to one state of being. UPDATE: Slack is, for now, back up. Will it remain so? Only time will tell. UPDATE 2: Slack access remains spotty for many. UPDATE 3: Slack access has been largely restored.