A few projects exist to provide free and open-source Unicode typefaces, i.e. Unicode typefaces which are open-source and designed to contain glyphs of all Unicode characters. However, there are also numerous projects aimed at providing only a certain script, such as the Arabeyes Arabic font. The advantage of targeting only some scripts with a font was that certain Unicode characters should be rendered differently depending on which language they are used in. Unicode fonts in modern formats such as OpenType can in theory cover multiple languages by including multiple glyphs per character, though very few actually cover more than one language's forms of the unified Han characters.