autodl-irssi is an advanced and easy to use torrent file downloader plugin for Irssi. The optional ruTorrent plugin (GUI) makes it even easier to use. The installer will set everything up. It works by connecting to your torrent tracker's IRC announce channel. You tell it exactly which IRC servers and channels to connect to and it does the rest. When a new torrent is announced, and matches one of the user filters, it's immediately downloaded. There's no delay like RSS, which polls once every 5-15 minutes. Once downloaded, the torrent file can be saved to a torrent client watch directory, sent to rtorrent, or uploaded to an FTP server. It supports more than 70 private trackers, and it's very easy to add your own if you know some basic XML and regular expressions. The filters are easy to set up, but also advanced. Some of the filters are release name, TV show name, torrent size, resolution, encoder, source, year, format, bitrate, medium, category, and many more. To prevent you from accidentally downloading too many files at once, you can also tell it to only allow X number of downloads per day, week, or month.
PyroScope is a collection of tools for the BitTorrent protocol and especially the rTorrent client. "pyrocore" is the component providing command line tools for automation of common tasks, like metafile creation, and controlling rTorrent via its XML-RPC interface. It also offers a documented API, with which these tools are implemented.