Apache is primarily used to serve both static content and dynamic Web pages on the World Wide Web. Many web applications are designed expecting the environment and features that Apache provides.
Apache is redistributed as part of various proprietary software packages including the Oracle Database and the IBM WebSphere application server. Mac OS X integrates Apache as its built-in web server and as support for its WebObjects application server. It is also supported in some way by Borland in the Kylix and Delphi development tools. Apache is included with Novell NetWare 6.5, where it is the default web server. Apache is included with many Linux distributions.
Apache is used for many other tasks where content needs to be made available in a secure and reliable way. One example is sharing files from a personal computer over the Internet. A user who has Apache installed on their desktop can put arbitrary files in Apache's document root which can then be shared.
Programmers developing web applications often use a locally installed version of Apache in order to preview and test code as it is being developed.
Microsoft Internet Information Services (IIS) is the main competitor to Apache, followed by Sun Microsystems' Sun Java System Web Server and a host of other applications such as Zeus Web Server or Nginx.