These ebuilds come from http://code.google.com/p/gentoo-china-overlay.
If you have some problems, go to the official site first.
xecjk : xeCJK is a package written for XeLaTeX which allows users to typeset CJK scripts easily ( http://bbs.ctex.org/viewthread.php?tid=40232%26extra=page%3D1%26page=1 )
zhspacing : zhspacing fine-tunes several details in typesetting Chinese using XeTeX and XeLaTeX ( http://code.google.com/p/zhspacing/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a gentoo-china
For Paludis use this rsync : rsync://gentoo.zugaina.org/gentoo-china-portage
If you have a problem : ycarus(-at-)zugaina.org