PowerISO is a proprietary programs that has created a file format called DAA (Direct Access Archive). These files work like RAR (file format) files. They compress a file or files into smaller uniform sized file, in the formate file_name01.daa, file_name04.daa, file_name03.daa, ... PowerISO is a windows program, but they have made a command line Linux programs to open, extract and convert their files.