The Roxen Challenger is a modular web server .

RXML
Content on web pages is written using HTML, a text format with mark-up in the form of <tags> telling the browser how the content should be displayed. Challenger comes with its own macro language, RXML, that uses tags like the ones in HTML. RXML is never sent to the browser though, but Challenger converts all RXML tags into HTML using the RXML parser.

RXML can be used for a number of things, such as creating graphical headings and diagrams, connecting to databases or creating dynamic pages or all of the above. The bulk of this manual describes the various RXML tags and how they can be combined. The key to RXML is that each tag solves a separate task. Hence several tags can be combined to perform an even greater task.

Modules
Roxen Challenger uses a system of modules. The different functions of Challenger is handled by different modules. Modules are enabled and configured through the configuration interface by the administrator. Many modules handle different RXML tags, therefore, which RXML tags can be used depends on how the administrator has configured the virtual server. The documentation for each tag includes information about which module handles it, if a tag is not available, the administrator can add the proper module to the server to enable the tag.

Modules that handle RXML tags can be written by third-party developers or any programmer with sufficient knowledge of pike and Roxen. It is also possible to create packages of RXML tags, for use with the <use> tag. Apart from the RXML tags in this manual there can be additional tags available at a Roxen site.