関連ワード:  is open source software always free    open source software is always free of cost    open source software is always free to use and modify    open source office software is always free of charge    free and open source software foss is always distributed at no cost to the user    open source software is always free.true or false    is all open source software free    is open source always free    is open source really free  
結果 : is open source software always free