===== Overview =====
[[http://www.libgd.org|libgd]] is an open source library that allows developers to dynamically generate images.  It is integrated with PHP.  

===== Case Studies =====
  * Audiogalaxy.com used it to build graphs of music popularity over time.  We also used it to chart internal statistics.

===== Gotchas =====
  * 

===== Tips & Tricks =====
  * Consider caching your images after generating them to reduce CPU usage.


===== Alternatives =====
  * For generating charts of things like bandwidth or file system usage over time, consider [[rrdtool]].
  * For drawing abstract graphs and networks, consider [[http://graphviz.org/|Graphviz]]

===== Other Resources ==== 
  * The [[http://news.php.net/php.gd.devel|libgd discussion archive]] may help you find answers to problems.