@rvlobato One thing that article doesn't mention is that, if you want the LibreOffice/OpenOffice or Standalone LanguageTool options to be as smart as the hosted service, you'll need an SSD and to download the optional 8GiB (compressed) bundle of n-gram data in addition to the hand-written rules it comes with by default.
https://languagetool.org/compare
http://wiki.languagetool.org/finding-errors-using-n-gram-data