I posted these examples to the Csound list yesterday and some folk suggested I post them here too. It's just a really simple Processing applet that controls an instance of Csound through OSC commands. There are more complex ways of getting Csound to speak with Processing and vice versa, in particular see Jim Haeron's article http://www.csounds.com/journal/issue11/Processing.html. If anyone has any questions please free to leave comments. Likewise if anyone makes any improvements please post updates. It should be easy to build GUI interfaces in Processing to control Csound, sliders buttons and XY pads could be added to the Processing applet to control parameters in Csound.
Rename OSCMouse.txt to OSCMouse.pde and make sure you start Csound before running the Processing applet.
*********You will also need to install oscP5, Brain has given details below************