"Mac OS X" is how it is written on the Apple website

README

@@ -48,8 +48,8 @@ Supported kernels:
    Full functionality requires Linux 2.2.x or better.  A large fraction of the
    code should run on just about anything.  While the current code is fairly
    Linux specific, it should be fairly easy to port the majority of the code
-   to, say, FreeBSD or Solaris, or MacOsX, or even Windows (if you are into that
-   sort of thing).
+   to, say, FreeBSD or Solaris, or Mac OS X, or even Windows (if you are into
+   that sort of thing).
 
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