Gentium (Latin for of the nations) is a Unicode serif typeface designed by Victor Gaultney. Gentium fonts are free and open source software, and are released under the SIL Open Font License (OFL), which permits modification and redistribution. Gentium has wide support for languages using the Latin, Greek, and Cyrillic alphabets, and the International Phonetic Alphabet. Gentium Plus variants released in November 2010 now include over 5,500 glyphs and advanced typographic features through OpenType and Graphite.

Read more about Gentium:  Open Source Development