Mumble is a low latency chat server. You join a server, people join your channel, you chat. Its designed for public group conversations, like in games. Tox is

Mumble is a low latency chat server. You join a server, people join your channel, you chat. Its designed for public group conversations, like in games. Tox is more like Skype, but it has no central server. You add friends to a buddy list and chat with them, you add more people to the chat and it becomes a group chat.