Trac supports inserting HTML into any wiki context, accomplished using the HTML WikiProcessor.
HTML support is built-in, and does not require installing any additional packages.
To inform the wiki engine that a block of text should be treated as HTML, use the html processor.
This example should explain:
#!html <pre class="wiki"><code> #!html <h1 style="text-align: right; color: blue">HTML Test</h1>
</pre> </code>
Results in:
#!html <h1 style="text-align: right; color: blue">HTML Test</h1>
Note that Trac sanitizes your HTML code before displaying it. That means that if you try to use potentially dangerous constructs such as Javascript event handlers, those will be removed from the output.
See also: WikiProcessors, WikiFormatting, WikiRestructuredText