関連ワード:  two features of open source software    two advantages of open source software    two characteristics of open source software    state two features of open source software besides the fact that it is available freely    state two features of open source software 2    write any two features of open source software    two advantages of using open source software    two major characteristics of open source software licenses are    write any two common features of open source software    give two other characteristics of open source software