There are a number of extremely popular modules for the Apache web server that are not included in the basic distribution. Most of these are separate because of licensing or support reasons; some are not distributed by the Apache Software Foundation because of a decision by the Apache developers; and some are integral parts of other projects. For instance, mod_ssl for Apache 1.3 is developed and maintained separately not only because of the U.S. export control laws (which were more restrictive when the package was originally developed), but because it requires changes to the core software that the Apache developers chose not to integrate.
This chapter provides recipes for installing some of the most popular of these third-party modules; when available, there are separate recipes for installation on Unixish systems and on Windows.
The most comprehensive list of third-party modules can be found in the Apache Module Registry at http://modules.apache.org/. Some modules are so popular or complex that they have entire sites devoted to them, as do the ones listed in this chapter.
Although hundreds of third-party modules are available, many module developers are only concerned with their single module. This means that there are potentially as many different sets of installation instructions as there are modules. The first recipe in this chapter describes an installation process that should work with many Apache 1.3 modules, but you should check with the individual packages' instructions to see if they have a different or more detailed process.
Many of the modules are available from organizations that prepackage or distribute Apache software, such as in the form of an RPM from Mandrake or Red Hat, but such prebuilt module packages include the assumptions of the packager. In other words, if you build the server from source and use custom locations for the files, don't be surprised if the installation of a packaged module fails.
All of the modules described in this chapter are supported with Apache 1.3 on Unixish systems. Status of support with Apache 2.0 on Windows is shown in Table 2-1.