A Question On Graphics?

[Thomas Dineen]

Gentle People:

     Sorry if this appears off topic but I am not sure where to post the
question. Please do not get mad, just recommend a better venue!

     Currently I am quite experienced with C and learning C++ but I have
never written graphical type applications in either!

     Can you recommend an open source graphics package which would be
called by C/C++ and be fit for drawing complex graphs and charts for Web 
Applications?

    Also I have successfully experimented with Apache and PHP but have 
not yet
identified graphics applications for this venue either! Ideas?

     I am thinking about calling a C/C++ based application called from 
Apache/PHP,
where the C/C++ Application would call the graphics application as 
necessary!

    Is this the best architecture?

Thanks for the help.
Thomas Dineen