which library (ulibc or glibc) used in tinycore build level.

[int91h]

Dear tinycore developers
I am looking for a starting point to build a fast-boot os related in my msc project.
I've been very impressed by TinyCore and i want to contribute in TinyCore project.
i have some questions
-I found both ulibc and glibc in http://distro.ibiblio.org/pub/linux/distributions/tinycorelinux/2.x/release/src/
which  library (ulibc or glibc) used in tinycore build level. I found compiletc.tce used glibc library. Does it means that tinycore used glibc library in build level.
 have it  any influence in tinycore (or other os) boot time that which library have  used.
Thanks in advance

[curaga]

Glibc is used everywhere except ldconfig, which is from uclibc because of its small size.