In principle, one can do anything with the Common Gateway Interface (CGI). But the range of problems for which CGI provides a good solution is much smaller!
The same is true of a content generator in Apache. It lies at the heart of processing a request and of building a web application. Indeed, it can be extended to do anything that the underlying system permits the webserver to do. The content generator is the most basic kind of module in Apache.
All of the major traditional applications normally work as content generators. For example, CGI, PHP, and application servers proxied by Apache are content generators.
In this chapter, we will develop a simple content generator. ...