What is a "toy" language?
magicobject: PHP simply lacks the facilities that professional developers need. Inability to override class methods and lack of threads are two obvious but extremely important examples. There are many other reasons to call it a toy language, inconsistent interfaces, bolt-on object-orientation poor variable scope rule in classes which mean you need $this everywhere and the really poor excuses that the PHP development team seem to come up with for the lack of appropriate development all contribute to keeping PHP as a novice and hence toy language. All these problems are addresses in other modern OO languages like Java, C#, Ruby. 
All in all its not a language you should use for a long-term project eventually you just keep rubbing up against its limitations.