Alkali-free glasses are disclosed having (in weight %) 50≦SiO2≦80%, 2≦Al2O3≦17%, 8≦B2O3≦36%, and greater than or equal to 2% and less than or equal to 25% of at least one of CaO, MgO, BaO, SrO or ZnO. The alkali-free glasses can have a surface layer with greater than 0.2 weight % N. Such alkali-free glasses are achieved by nitriding processes and exhibit increased strength, scratch resistance and chemical durability.