PHP Graphing Library
I recently did search for an open source PHP graphing library. Besides the well known but non-free JpGraph library, I found many simple ones either for bar graphs or pie graphs. Until I stumbled across Zack Bloom's Advanced Graphing Class. It does pie, line and bar graphs including function plotting and has a plethora of options to set. Most notably is it's ability to autoscale graphs depending on the input data.
Unfortunatly it was only available for PHP5. I'm still running PHP4 and many others do as well, so I ripped out all PHP5 syntax and made it run on PHP4. I also removed the capability to output JavaScript graphs instead of images, because I didn't need this feature. The library is licensed to the public domain, but comes with an Arial truetype font. I wasn't sure about the license of that font so I replaced it with the really free Bitstream Vera font.
If you need a graphing lib for PHP4 you can download it or do a darcs checkout. Maybe someone could use this lib for a nice DokuWiki plugin?