We have a web application that will have a text messaging feature. The messages need to synchronize in real time. My first thought was to use service workers but the problem is that the application is served from each client's own server and service workers require SSL. It is not feasible to install an SSL certificate to every client server. There is a central server that handles the messaging but the application will always be served from individual distributed servers without SSL. So basically, the problem is being able to push updates to the application without using HTTPS. Polling would be a simple but not very good work around. I was looking into integrating XMPP for the messages but after some research, I still don't know if that would work. The application servers are Apache with PHP.