RARPlayer

RARPlayer is a tool that can play videos from torrent files, so you don't have to download them anymore. The interface of the program consists of a plain window which doesn't offer any special options.
Once you initiate RARPlayer, your next step is to open the file with the TORRENT or TSTREAM format, select the video of your preference (if the respective torrent lists several video files) and then give the software some time to load it.
Evidently, you cannot navigate back and forth in the program. All you can do is pause and resume the video, adjust the volume or switch to fullscreen mode.
The tool uses a very high amount of system resources and, sometimes it is not able to load a file or takes a very long time to do so. Of course, this depends on the number of available seeders that your computer links to, since RARPlayer relies on peer-to-peer connections.
On the other hand, the software recognizes most commonly used video formats, including DVDs and Blu-rays. While trying to load a video file, RARPlayer initiates a pre-buffering process, waits for sufficient download speed and alerts you that a video may not play properly since the bitrate is unknown. In addition, you can only load a new file by exiting and reinitiating the program.
There is no help file you can access, but there is a log file containing all errors encountered by RARPlayer which you can view (beginners would have a really hard time understanding all the technical details behind it).
Unfortunately, the program found errors every time we loaded a torrent and it also crashed a couple of times when we tried to close the application.
Taking all the ups and downs into consideration, RARPlayer is a software that's worth keeping an eye on. Right now, however, it does a good job on random occasions. So, debugging and improvements are highly welcomed.