Calais is a tool that analyzes user-submitted text to instantly create rich semantic metadata. Essentially, upon the examination of a user-submitted document, Calais generates entity identification tags. Users may utilize such tags in content management systems, blogs, applications, etc.

Unlike classic entity identification services, Calais also provides users with additional entity tags that may be concealed within submitted text. In doing so, Calais helps to make online content more accessible.

Calais is a free service for commercial and non-commercial use.