Why would they need to include chat services? External chat clients already exist, and for the important internal messages, there are systems for communication:

Why would they need to include chat services? External chat clients already exist, and for the important internal messages, there are systems for communication: - StackExchange has a comment system, as well as a Meta discussion board, as well as chatrooms for every StackExchange site - GitHub has commit messages and issue tracking, as well as e-mail addresses listed for contact, and in-project e-mail threads So these sites really do have chat, just not the Facebook-Messenger type of chat that you might be thinking of.