Pretty nice it seems (though I've never used the program). Can render up to HD resolution and no watermarks. http://www.sidefx.com/index.php?option=com_content&task=view&id=1002
It seems that here is the free apprentice version, which has things like limited resolution for renders and watermarks etc. and the $99 version doesn't have those. I think it's all the features but not for commercial work <shrug>. Might have a dig through some video tutorials at some point and see if I want to try this or…