All credit is given, none are from commercial games (unless ofcourse they made their textures free as in freedom... I doubt they would tho), all are OpenSource+Free. (Brick textures look like brick textures, metal floor ones look like metal floor, Im sure some of these are inspired by textures the artists saw in commercial games tho... they are a great source of insperation because they look so good :P ). The textures I made are both GPL and FDL and the other textures on the site are using an assortment of licences. The GPL shoulden't give you any trouble tho, it's media... quite hard to link into code.