Quick questions about Arduino developments

Hi!
I see "A lot of the so called "shields" are used in our commercial projects and are working"

Is it means that some shields no open source?
Could we use them in our play project(no commercial projects ) ?

and could you tell me which software you uesd to design the board? I don't know how to open ".brd" ,and how to chang it to Gerber file ?

thank you !