Open-source Unicode typefaces

Screenshot of type set in several different free (libre) sans-serif typefaces: Latin Modern Sans, Liberation Sans, Arimo, FreeSans, Nimbus Sans L, Tex Gyre Heros, Droid Sans, Roboto, Noto, Bitstream Vera Sans, and DejaVu Sans.
Examples of several libre, sans-serif typefaces.

There are Unicode typefaces which are open-source and designed to contain glyphs of all Unicode characters, or at least a broad selection of Unicode scripts. 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, and that a font that only includes the characters a certain user needs will be much smaller in file size compared to one with many glyphs. 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.