Finnish spell checker and hyphenator extension for LibreOffice. The extension is available for Windows (XP, Vista and 7) and Mac OS X (10.5/Intel and later).
LibreOffice 3.3 or later is supported on both platforms. Linux users may use the packages provided by their distribution (these are available at least for Ubuntu, Debian, Fedora, OpenSUSE and Mandriva).
For more information, see the full list of supported platforms. Note that the information on these pages is mostly in Finnish.