PHP vs. Python vs. Ruby

I did an interesting programming language comparison last semester and wrote up a paper called "PHP vs. Python vs. Ruby – The web scripting language shootout". I'm not completely satisfied with it as it does not dig deep enough into the details, but it provides a good introduction and overview. As my time was limited and the seminar was only worth 3 ECTS, further investigation and experiments were not done - I would appreciate any additional references on this topic, feel free to post a comment or contact me.