Do I need to install anything to watch videos on Porkolt - Video Sharing and Social Network (http://www.porkolt.com). None of the videos play on my PC, thanks.

Check the site? What video formats do they use. What happens when you try to play one?

I press play and the video just goes black, nothing else happens

That doesn't answer all my questions.

I'm not sure about the format, I've tried contacting the site several times but they haven't replyed. Do they work on your PC?
Porkolt - Video Sharing and Social Network (http://www.porkolt.com)