Systems and techniques to facilitate communications among individuals in an enterprise may use collaborative conversation channels that are associated with specific communities within the enterprise. In general, in one implementation, the technique includes defining communities within an enterprise and providing access to collaborative conversation channels through a user interface. Each collaborative conversation channel is associated with a specific community and has an associated set of message types. A request to send a message of a selected message type within one of the collaborative conversation channels may be received through the user interface. In response to the request, the message may be sent through the collaborative conversation channel.