I'm not a big fan of PHP. Also, I didn't like the way that the current PHP reports were setup - specifcally the HTML was, well, wrong (not even HTML 3.2 compliant). So I took a little time and effort and re-wrote the three RTG CGIs in perl. They leverage CGI.pm heavily for display.
To use them, you may need to make 3 edits. First, change the shebang line to your location of perl (/usr/local/bin/perl by default). Second, edit the $config line to point to your rtg.conf (/usr/local/rtg/etc/rtg.conf by default). Third, change the $relative_image_directory line to point to the relative URL of where the RTG images, rtg.png and rtgback.png, are located (/rtg by default).
Also, there is no semblance of security or data checking built-in to the scripts. If you are going to use them, I STRONGLY recommend that you at least protect them with some Authentication, Authorization and Access Control.
Thanks for these CGIs go to Corsis, which donated my time towards developing them.
Here are the perl sources: