The State Library of Württemberg (German: Württembergische Landesbibliothek or WLB) is a large library in Stuttgart, Germany, which traces its history back to the ducal public library of Württemberg founded in 1765. It holds c. 3.4 million volumes and is thus the fourth-largest library in the state of Baden-Württemberg (after the university libraries of Freiburg, Heidelberg and Tübingen). The WLB owns an important collection of medieval manuscripts as well as one of the largest bible collections in the world.
The WLB is one of two state libraries of Baden-Württemberg, the other being the Badische Landesbibliothek (BLB) at Karlsruhe
More information on the Wikipedia pages [1] (English) and [2] (German). The English language part of the website is at http://www.wlb-stuttgart.de/en.