Commandos Franchise & Graphics

  1. I was just curious how initial games of the Commandos franchise were created. The likes of Behind Enemy Lines & Beyond the call of duty. Just wondering which game engine/framework was used and how animation was performed in the maps like streams of flowing water and footsteps on the snow etc.
    Did some googling on this but not able to find any satisfactory answer.

  2. Can anyone also please guide me to the top 3 websites offering good quality game graphics and sprites for free?
    I did googling on that but need expert opinion as well.

Thank you in Advance.