Rendering graphical charts with PHP: tools / best practices
We are using Google Chart to render graphical images, but 500 requests / days was not enough. Which PHP classes / frameworks are worth looking at?
JpGraph and GraPHPite are the most common open source packages. I recommend GraPHPite, in particular, it has a slightly better API and gives better graphics.
Edit: I recently developed a small charting library to fetch database data, process it with PHP, and create Google Analytics style Interactive charts (using flot to display client side charts). It is basically a complete server / client solution for converting database tables to graphs.
The Google Chart API no longer has a 500 requests / day limit. I remember how that changed a couple of months ago.
While this is not a PHP solution, we are using amCharts for charts in our application. They are based on Flash but look fantastic and allow users to zoom in to a graph. Graphs are drawn simply by generating XML with your data.