The document discusses the development of a computer-mediated communication (CMC) application to support language learning based on social and cognitive presences. The application is designed using the Community of Inquiry framework, which emphasizes social, cognitive, and teaching presences. It incorporates several functions like a chatbot, causal maps of chat discussions, and visualization of participation. An initial formative usability evaluation with students found the causal maps and participation features positively supported social and cognitive presences, while the chatbot required improvement. Future work will evaluate effects on language learning and further refine weaker functions.