We have gone through the basic concepts of Opa and now it's time to build a real web application. In this chapter we will build a chat application. The application offers one chat room. The users who connect to the application will join the chat room automatically and can start discussing immediately. For simplicity, we supply a random username when a user joins. The source code for this application can be found at https://github.com/winbomb/opapackt.
The following is a screenshot of our chat application: