Newsbin is a Windows-only program; there is no Macintosh version. If you do most of your downloading with NZB files, you might like our Super-NZB downloader. If you want to download binaries directly from newsgroups, then take a look at our NewzScape downloader.
We make several kinds of specialized Usenet/NZB client programs. All of them run on Mac OS X, as well as Windows.