At this point, we have everything we need to write PHP applications. Web application development is, in essence, a form of client/server development. By installing a fully functioning version of Apache and PHP on our machines, we have created a server environment that (hopefully) closely mirrors our environment in production. Since Eclipse is written in Java, we need a Java Virtual Machine on our systems. Using Eclipse and PHPEclipse, we can now begin writing applications for this server environment.
Later on, we will cover more advanced topics like debugging and database interaction. These chapters will require more software to be installed, and we will also walk through those installations when relevant. For now, though, we can start using Eclipse.