Carl Grüninger Ltd. operated in Stuttgart from 1867 as a general book publisher. In 1888 it started publishing the Neue Musik-Zeitung, which had been published by P.J. Tonger of Cologne from 1880 to 1887. Among its books were a few on musical topics, such as Rudolf Louis' and Ludwig Thuille's Harmonielehre (1910), some music history texts and at least a few music scores such as Hermann Grabner's Konzert im alten Stil Op.1, for 3 violins (1915). The last musical item was a book issued in 1928.
In 1897 Ernst Klett and his brother-in-law, Julius Hartmann, took over the firm, and it has remained in the Klett family to the present day. Now known as , it has grown into a holding company with interests in educational businesses of all kinds, from textbook publishing to kindergarten management and educational software.