Windows does not provide a POSIX environment by itself, so some sort
of emulation library is required in order to provide the necessary
functions. There are several ports of Ruby for
Windows: the most commonly used one relies on the GNU Win32
environment, and is called the ``cygwin32'' port. The cygwin32 port
works well with extension libraries, and is available on the Web as a
precompiled binary.
Another port, ``mswin32,'' does not rely on cygwin. It is currently
available as source code only. The remainder
of this chapter will refer to the cygwin32 port.
