I\'m trying to build a stock analysis application and it uses 3 kinds of charts
if you are using a server side language there is plenty of libraries that you can use and draw images and of course it can be a chart, also there are some Libraries specifically for drawing Charts.
But here are some really good JavaScript chart Solutions
HighCharts Offer a free licence for non-commercial use, based on jQuery
GRaphael MIT Licence , based on the famous raphael library
Flot With less interaction but still free
JSCharts A non-free alternative
The Good point about JS is that it can be interactive.