Mac OSX Command-Line is Partially Case Insensitive

I've recently noticed a behavior in the command-line in Mac OS X. This environment, like all *NIX environments, is case sensitive. Typing:
cd /Library

is different from typing:
cd /library

To UNIX, /Library and /library are different directories.

However, I've found that in Mac OS X, typing either of those commands will put me in the same directory. Mac's brand of UNIX seems to be case-insensitive. Weird.

Actually, this has to do with the filesystem, rather than UNIX. Mac's default filesystem is HFS+(Journaled), which is not a case-sensitive filesystem. So the Mac command-line behavior honors this since, on the filesystem, which is at a lower level than the command line, there is no difference between /Library and /library. The command-line environment will, however, mimic case-sensitivity on HFS+ filesystems to a certain degree. For instance, tab-completion of file paths is case sensitive. But typing full file paths seems to default to the case sensitivity of the active filesystem. In fact, if I ssh to a UNIX box or an NFS mount on a UFS or ext3, or other case-sensitive volume, things work as expected in the *NIX world.