E-Libretto: A collection of more than 200 electronic opera libretti, full text.
English Opera Translations: English performing translations (librettos) of popular operas, including Marriage of Figaro, La Boheme, Gianni Schicchi, Pagliacci, translated by Ken Jakobs.
Karada Classical Music: Opera's Librettos: Biographies of composers and lists of their works. Includes libretti for the works of some of them.
Libretto Homepage: Public domain opera libretti and other vocal texts.
OperaGlass: Operas: Extensive directory by opera of libretti, synopses, performance history, background and discography.
Opernführer / Opera Guide: A collection of opera libretti (originals and translations), with links to similar sites. [German/English]