Development-Stage Modules
Modules to Aid Debugging
Control and Monitoring Modules
Server Configuration Modules
Authentication-Phase Modules
Authorization-Phase Modules
Access-Phase Modules
Type Handlers
Trans Handlers
Fixup Handlers
Generic Content-Generation Modules
Application-Specific Content-Generation Modules
Database Modules
Toolkits and Frameworks for Content-Generation and Other Phases
Output Filters and Layering Modules
Logging-Phase Handlers
Core Apache Modules
Other Miscellaneous Modules

Many third-party modules have been written to extend mod_perl's core functionality. They may be distributed with the mod_perl source code, or they may be available from CPAN. In this chapter we will attempt to group these modules based on their functionality. Some modules will be discussed in depth, but others will be touched on only briefly.

Since most of these modules are continually evolving, the moment this book is published much of the information in it will be out of date. For this reason, you should refer to the modules' manpages when you start using them; that's where you will find the most up-to-date documentation.

We will consider modules in the following groups:

Modules used mainly during the development process

Modules that assist in code debugging

Control and monitoring
Modules to help you monitor the production server and take care of any problems as soon as they appear

Server configuration
Modules used in server configuration

Modules used to facilitate authentication

Modules used to facilitate authorization

Modules used during the access-verification phase

Type handlers
Modules used as PerlTypeHandlers

Trans handlers
Modules used as PerlTransHandlers

Fixup Handlers
Modules used as PerlFixupHandlers

Generic content-generation phase
Generic modules that assist during the content-generation phase

Application-specific content generation phase
Non-general-purpose content generators

Database-specific modules

Toolkits and framework for content generation and other phases
Mostly large toolkits and frameworks built on top of mod_perl

Output filters and layering
Modules that filter output from the content generation stage

Logging-phase handlers
Modules that assist during the logging stage

Core Apache
Modules that interface with core mod_perl

Modules that don't fit into any of the above categories