I know kernel have different ,for example: Linux kernel and Freebsd kernel.
But I don't know which is better in these,who can tell me?
Thanks in advance.
And who have good idea about study kernel?
Happy hacking!

Hey there friend,

This might be a tad bit late to reply to your post, but here goes...

Now I'm quite not sure what your last question means or what your getting at exactly with - "And who have good idea about study kernel?" but being that I have taken an interest in the Linux kernel myself, I can however direct you to some links and resources about the Linux kernel, and hopefully anybody who takes an interest in learning about the Linux kernel will find these links useful as well.

1.) http://kernelnewbies.org/

2.) http://janitor.kernelnewbies.org

2.) http://bravo.ce.uniroma2.it/kernelha...006/#resources

3.) http://kernelbook.sourceforge.net/

4.) http://kerneltrap.org/

5.) http://www.linuxchix.org/content/cou...ernel_hacking/

* 6.) http://www.kroah.com/linux/

misc: http://www.youtube.com/watch?v=L2SED6sewRw (49 minutes, pretty long)

In addition to these links I find these books good reading material:

1.) "Linux Kernel in a Nutshell" by Greg Kroah-Hartman
O'Reilly Media, Inc. (December 14, 2006)

2.) "Understanding the Linux Kernel, 3rd Edition" by Daniel Bovet, Marco Cesati
O'Reilly Media, Inc.; (November 17, 2005)

3.) "Linux Kernel Development, 2nd Edition" by Robert Love
Novell Press; (January 22, 2005)

4.) "Linux Device Drivers, 3rd Edition" by Jonathan Corbet, Alessandro Rubini, Greg Kroah-Hartman
O'Reilly Media, Inc.; (February 7, 2005)

(*One can find all the books stated above at amazon.com)
(*Needless to say, but for the sake of brevity - you should know C programming if you wanna dabble or tinker with the code of the Linux kernel)

Hope this helps even a bit! ^^

Thanks very much!