Not UNIX emulation. It implements some functions from POSIX standards.
It's needed because Windows9x and WindowsMe do not have the POSIX
compatibility libraries. NT, of course, does have the libraries, but the
Yukihiru Matsumoto does not use Windows ;)))

# -----Original Message-----
# From: Jose Rodriguez [mailto:tub4jxr / hotmail.com] 
# Sent: 28 ??????? 2001 ?. 8:37
# To: ruby-talk ML; undisclosed-recipients:
# Subject: [ruby-talk:20456] Cygwin DLL - What does it do?
# 
# 
# My apologies for this question, but what does the CYGWIN dll 
# do on the windows platform.  Is it used only for the 
# emulation of a Unix environment on the WIN32 platform?  Or is 
# there something else in addition that it does??
# 
# Thank you all.
#