Polyglot Wikipedia lets you navigate easily between articles in languages of your choice. Select them on the preferences page and choose your options. It can display hyperlinked titles of the current article in all available languages. It can also highlight your languages and move them to the top of the list in the sidebar for quick access.
Supports other Wikimedia projects listed on http://www.wikimedia.org/
This extension is based on Multi-Language Wikipedia Titles by Øyvind Rønningstad and Wikipedia+ Language Bubble by damncandy – extensions for Presto-based Opera.
Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. This is not an official extension and the author is by no means related to the aforementioned foundation.