Apache is a fantastic piece of software. It happens to be a large piece of software. If a program's codebase is allowed to grow without testing and refactoring, bugs will creep in! Happily, Apache remains refreshingly well organized, stable, and secure — just what you look for in a server.
One of the ways the Apache developers maintain performance and stability is by adding features as modules. The wsgi module, for instance, allows Apache to pass requests to a Python program like Django for fulfillment. For Apache setups that don't require this functionality, the wsgi module remains disabled, not affecting performance, stability, etc.
As you might guess… this page was served to you by an installation of Apache!