These libraries are part of the linux compatibility options
for FreeBSD.  To get linux compat working you will need

1) A linux binary such as doom, Wingz, or maple

2) these libraries

3) the linux compat lkm (ie run /usr/bin/linux)

then run the linux binary. 

The kernel option `COMPAT_LINUX' is not necessary for -current, or 2.2.
It *is* necessary for -stable, and the RELEASE's.

eric.
erich@FreeBSD.org