Rah_function turns every PHP function into a Textpattern tag. That’s right, with rah_function pretty much any PHP function can be used as a Textpattern tag. No need for PHP snippets, ending nor closing PHP tags — only thing you need is a Textpattern’s XML tag.
Need all caps? Can do:
<txp:rah_function call="mb_strtoupper"> Hello World! </txp:rah_function>
One might be unsure what the date is:
<txp:rah_function call="safe_strftime"> %B %d, %Y %H:%M </txp:rah_function>