Electronic Resources: German Language and Literature

Mediaevum.DE
Comprehensive portal for medievalists and scholars of medieval German literature: dictionaries, full texts and full-text databases, digitized images, current worldwide research projects, conferences, jobs, etc.
Index
Texts
Handbooks and Databases
Dictionaries and Indices
Manuscripts and Early Prints
Ongoing Research Projects

Europeana
Massive new Europe-wide project with many partner institutions.  Search for artworks, manuscripts, texts, etc., and view the original information in context.

IMAREAL (Institut für Realienkunde des Mittelalters und der frühen Neuzeit)
A database of material objects, themes, gestures, etc.  Right now, you can only browse the images, but they are adding a search feature soon.