Stackoverflow.com is really good at discussing these kind of issues, and the question has beeen asked and answered many times already as I found out with a bit

Stackoverflow.com is really good at discussing these kind of issues, and the question has beeen asked and answered many times already as I found out with a bit of googling. http://stackoverflow.com/questions/761194/interface-vs-abstract-class-general-oo http://stackoverflow.com/questions/761194/interface-vs-abstr... http://stackoverflow.com/questions/479142/when-to-use-an-interface-instead-of-an-abstract-class-and-vice-versa http://stackoverflow.com/questions/479142/when-to-use-an-int... More discussions can be found in Related questions.