We are looking for a lightweight persistent chat application that we can use both internally as well as with outside groups or partner organizations that we are collaborating with on specific projects. Are there any such apps that allow users from partner organizations to have full access to a specific chat room, but no access beyond that?
Specifically, we want users from partner organization A to be able to join the "Collaboration with group A" room but not see that we also have a "Collaboration with group B" room. So our requirements are to allow outside users to:
- Be invited individually to a persistent chat room
- Have full access to the regular chat features, including read/write, viewing chat history, attachments etc (neither Campfire nor HipChat allow this for their "guest" users)
- Only see that chat room, including not seeing what other chat room names exist (making outside users full app users let them see the names of other chat rooms).