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-RELEASE or newer.  It *is* necessary for -stable, and the
earlier RELEASE's.

* if you add new libraries, you should run
  /compat/linux/sbin/ldconfig to update the caches.

* if you have libraries you'd like to see included in this
  collection, send me mail.

eric.
erich@FreeBSD.org