We are considering an enterprise chat app for our company. However, we have significant presence in China and Indonesia. Local regulations of these countries require personnel data of these companies to be hosted locally. Also, some apps like Hangout are not accessible in china. We also need integration with Active Directory. We would also like to have video/audio chat/file sharing capabilities. We also want it secure.
As such, we are looking for open source alternatives that we can have a full control over the chat function. Any suggestions?