some question about newlib

[miloody]

Dear all:
my questions are:
1. Would anyone show me where I can find the document that describes
the difference of newlib and uclibc?
    In my opinion, it seems another clib that is smaller than uclibc, right?
2. some one told me newlib is a standalone clib, that means I can run
it on cpu with kernel support.
    But I still see the system call in newlib source.
    Do I search the wrong place or it really is?
appreciate your help in advance,
miloody