The site is in English, and features very useful information. For example, on the Research section there’s a list of documentation you can get about the evolution of music in China. There are insightful pages, like the one about the history of rock in China, or the one about electronic music in China. There is a lot of material to read on this site, and the best thing is that, as a wiki, it is open to everybody to edit it and to add more useful information to share.
If you are musician in China, your name should be there, and if you are a melomaniac the documentation found on RockinChina is pretty nice, and truly needed. Their wiki is a rescue buoy for Chinese rock researchers, giving the basic information needed to get into the music.
In summary, this is a a great stop for all music geeks wondering about the lay of the Chinese underground music scene.