There is a Mac version of MS Office. But Word is much worse than the Windows version.
Is there any emulator and howto to run Windows-native versions of Word on OS X?
Yes there are 2 ways
1) Run Word under Wine wither the free version or Codeweavers' packaged up version - Crossover
2) Run Windows (you need a licensed copy) under a virtual machine e.g Virtual box (which is free), Paralells or VMWare Fusion
You caould also use Bootcamp to run Windows instead of OSX
There is CrossOver:
I've tried it once, looks okay and does the job. It does cost a bit though.
As Randolf Richardson has mentioned, WINE is also possible on OS X, although a bit harder to configure if I recall correctly. But it's free and of course the same functionality.
WINE, which you smartly included as a tag, should do it for you:
MacOSX - The Official Wine Wiki
WineHQ - Running Microsoft Word (various versions, lots of information)
In Google Image Search, I just came across this image which appears to be of a very recent version of MS-Office, most likely running under WINE (at least the page it came from was explaining something about WINE), with support for another language (or a very different looking font):
Of course, there are alternatives such as OpenOffice.org (OOo) that can read/write MS-Office files directly, and since it's free it's definitely worth a try as well. There are MacOS versions available for download for OOo:
OpenOffice.org (free and open source)