By default, s9e\TextFormatter escapes HTML entities. This plugins allows HTML entities to be used.
Note: while numeric entities such as  
are always available, the list of named entities such as ♥
depends on PHP's internal table.
Example
$configurator = new s9e\TextFormatter\Configurator;
$configurator->plugins->load('HTMLEntities');
// Get an instance of the parser and the renderer
extract($configurator->finalize());
$text = 'I ♥ HTML.';
$xml = $parser->parse($text);
$html = $renderer->render($xml);
echo $html;
I ♥ HTML.