Wget has already been ported to Windows, and because it's free software, you can try port it to any other OS. Opera, on the other hand, hasn't been ported to n

Wget has already been ported to Windows, and because it's free software, you can try port it to any other OS. Opera, on the other hand, hasn't been ported to nearly as many OSen, and you don't get the source to help with the effort (plus it's much larger than a CLI file downloading utility). Your idea of cross-platform is weird.