Please check http://www.xworkplace.org for available NLS packages. I only maintain English myself, but I try to keep track of the translations done by other people as time permits.
Note that NLS packages are version specific. That is, for a given &xwp; version, install only a matching NLS package, or &xwp; might malfunction more or less badly.
NLS packages are installed using WarpIN too. If you wish to use a language other than English, after &xwp; has been installed, do not restart your computer yet, but install your NLS package next. Then restart the WPS.
When several languages are installed, the
"&xwp; Setup" object offers you a
"Language" drop-down box to change the current language.