Multilanguage autoparse glossary.
Parses the output HTML and automatically inserts glossary definitions.
Glossary links opens up a AJAX-based tooltipbox showing the definition. (See screenshot in Wiki section.)
Supports multiple languages.
Also includes FE plugin for displaying the entire glossary.
If you like this extension, please rate it. http://typo3.org/extensions/repository/view/pmkglossary/current/rating/ As ratings are the only way I can see if there's an interest in this extension, updates depends on people rating it. (No ratings = No Updates!)
Not released at TER yet, due to problems uploading extensions to TER!