The messaging server is an example of something that would be highly concurrent; let's say we want to embed a web server into this to show the list of clients that are connected to the server. If you look at the flask, you can see how easily you can have a full web container in about eight lines of code.

The messaging server is asynchronous; therefore, it is callback based in C code. These callbacks can then call into Python roster object via Cython. Then, we can iterate over the roster dictionary to get online clients and simply return some JSON as a web service very easily reusing Python code and no need to write anything in C/C++.

It's important to note when embedding web servers is that they start a lot of threads. Calling the start web server function will block until it will exit, meaning if we start the web server first, we won't have the messaging server running concurrently. Also, due to the web-server function blocking, if we start it on a separate thread, it will...