Now, we are working as a co-author of phpBB Language pack.
Since we do have a forum powered by phpBB 3.1.6 in Chinese, and no active Simplified Chinese language author working on it. David Yin thinked about to join the translating project of Chinese.
After the original author of Chinese approval, here is the new release of it.
http://forum.g2soft.net/viewforum.php?f=29