title: PHP Open Source Shopping Cart. Need to choose one
body: <p>I will start a little project with a shopping cart. I will need to make several modifications in the shopping cart.</p>
  
  <p>So my question is "Which is the best PHP open source Shopping Cart" to work with and easy to modify.</p>
  
  <p>Give me some clues.</p>
  
  <p>Best Regards,</p>