Computer code is configured to support a conversation among participants over a communication network. The computer code is configured to (i) progressively store the incoming and outgoing messages of a conversation on a communication device, (ii) display the message history of the conversation on the communication device, (iii) provide rendering options on the communication device, (iv) selectively transition participation in the conversation between a real-time mode and a time-shifted mode and (v) designate an interrupt mode for the conversation.