LanguageTool is an open source, free spelling checker in languages such as Polish, English, French, German and several others. The program can detect errors that will not be detected by correction tools built into text editors or browsers, including grammatical and stylistic errors. The program is available as a .oxt plug-in that can be installed in LibreOffice or OpenOffice.

LanguageTool fully integrates with the spell-checking tool for these packages. Detected errors are highlighted in blue, right-clicking on them will help you learn more.