PHP Web development IDE
 

I am coming from a C++ background and am used to testing code by setting breakpoints, viewing variables in the debugger etc.

I am now doing web development (using the symfony framework). what I really miss is not being able to set a breakpoint when a particular action is performed (e.g. a url clicked etc). Is there a FREE (GPL or other license) PHP IDE that can allow me to set breakpoints etc as described above?