Libchart is a chart creation PHP library that can generate bar diagrams or piecharts. It is compatible with PHP4/5 (compiled with GD and FreeType) and requires no other dependency.

Libchart is released under the terms of the LGPL

Project homepage:
http://naku.dohcrew.com/libchart

Demo site:
http://naku.dohcrew.com/libchart/pages/samplecode/