From the Wikipedia page on Palais Porcia 
The Administrative Library of the Ministry of Interior, predecessor of the present-day library, was founded in 1849. It was based in the Ministry offices on Wipplingerstrasse, Venna, Austria. In 1897 the library moved into its own building on Marc-Aurel-Strasse, one year later it relocated to Hohen Markt. In 1925 the library relocated into recently remodelled Palais Porcia. Since the establishment of the First Austrian Republic the library remains a branch of the Federal Chancellery.
The library stocks a reference collection of Austrian laws and regulations and houses the information technology center of the Chancellery. Since 2000, the library gradually took over and digitized the collections of the Federal Government ministries. In 2006 it became Austria's principal uplink gateway to SourceOECD (Austrian OECD depositary).
As of 2010, the library loans books only to government employees. The reading hall is open free of charge to all visitors (photo ID required to enter).