Slack is used by roughly half of our company. Unfortunately our main IT manager hates it because she claims she never gets the notifications (but I don't think she used the Windows app, which I love). So she won't officially endorse Slack so we still have random people on random IM clients which is annoying. So I run Pidgin and Slack.
At work we use Mercurial which is tied directly into our ALM (CodeBeamer). I use Bitbucket for my personal projects though and I like it. I use the SourceTree app to interface with it. It's ok... better than Tortoise Workbench. But we also use a mercurial plugin for Eclipse which has a really nice integration.