HipChat is an application service provider that allows users to create and participate in chat rooms and send one-on-one messages with other people in a group-centric format.
Pro Self-Hosting available
If you are worried about third-parties getting access to your data you should consider self-hosting. With self-hosting you are in control over where your data is stored, who has access to it. You will also not be vulnerable to exploits of a third-party provider.