SABnzbd

SABnzbd is an open-source cross-platform binary newsreader. It simplifies the process of downloading from Usenet dramatically, thanks to its friendly web-based user interface and advanced built-in post-processing options that automatically verify, repair, extract and clean up posts downloaded from Usenet.

SABnzbd is totally free, incredibly easy to use, and works practically everywhere. SABnzbd makes Usenet as simple and streamlined as possible by automating everything we can. All you have to do is add an .nzb. SABnzbd takes over from there, where it will be automatically downloaded, verified, repaired, extracted and filed away with zero human interaction.