Thank you Neil, I have learned a lot from your reply. Neil Williams wrote:
[2] http://www.openembedded.org/ (the website appears to be down right now)
This seems alright from my place using TOR. -- Xu Benda Fundamental Science of Mathematics and Physics, Tsinghua University, Beijing, P.R.China, 100084 tel:86-10-51531861 http://learn.tsinghua.edu.cn:8080/2005012177