How to choice the Open source project about kernel?

[lx]

hi:
  How to choice the Open source project about kernel?
I'm a new one, and I want to practice the technology about kernel.
Please list some simple projects, thank you
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20121219/1930da37/attachment.html