In TiddlyWeb a renderer is a code system that takes a tiddler as input and returns an HTML form. It is used by the HTML serializer to generate the HTML content, usually turning wikitext syntax into HTML with a wikitext renderer, such as WikklyText or twikifier. This functionality was originally fully in the serializer, but it became clear with use that being able to support multiple syntaxes would be useful.

Two config items control how wikitext in tiddlers is rendered. They are wikitext.default_renderer and wikitext.type_render_map.

If the HTML form of a tiddler is requested //and// the {{{type}}} attribute on the tiddler is not set its content will be rendered by the default renderer. In TiddlyWebWiki WikklyText is used for rendering. If the TiddlyWebWiki package has not been installed, then the {{{raw}}} renderer is used, wrapping HTML escaped content in {{{

}}} tags.

If the HTML form of a tiddler is requested //and// the {{{type}}} attribute begins with {{{text/}}} //and// the {{{type}}} attribute is present as a key in wikitext.type_render_map the value in the map is used to identify the module which contains the {{{render()}}} method for that type.
See also: Can I get a rendered tiddler as JSON?