Translation hints:
Option "Öffnen Sie interne Verbindungen im widget" should be changed to "Interne Links im Widget öffnen"

Buttons could need tool tips like in the english version of the widget.
I would propose:
"Add bookmark here" -> "Lesezeichen hinzufügen"
"Hide/show content" - "Inhalt zeigen/verstecken"
"Visit the widget index page" -> "Widget-Übersicht öffnen"

Interface:
Regarding the latter option (widget index page): Why is it there? It's not something i need when searching in Wikipedia. Anyway, I supposed the button to link to the wikipedia-homepage of the corresponding language (because of the flag).

Would be nice if the content window was resizable, it's hardly possible to read an article with its current size. Also middle-mouse scrolling unfortunately doesn't work.

The position of the close button is not very nice when switching to the options page.
For some reason there's a dashed horizontal line at the bottom of the widget.

Regards,
Wolfgang

There are other countries too, where German is spoken. Austria, Lichtenstein, and Switzerland for example. Please make general downloads available there, too.