From wikipedia

The Tessar design patent was held by Zeiss for two decades, and licensed to Ross (optics) in the United Kingdom, Bausch & Lomb in the United States and to Krauss in France. Only licensed manufacturers were allowed to use the brand name "Tessar". However, Tessar-type lenses were widely made by many manufacturers under different trade names. The Minoxar 35/2.8 lens on the Minox M.D.C and GT-E is the fastest and widest Tessar type lens achieved so far by using lanthanum glass elements. The picture quality was outstanding.[2] Other Tessar-type lenses include the Schneider Xenar, Agfa Solinar, Rodenstock Ysar, Kodak Ektar, Yashica Yashinon 80mm (twin-lens-reflex design), and Minolta Rokkor 75mm (twin-lens-reflex design).