Wikipedia
Operabase
Operabase is an online database of opera performances, opera houses and companies, and performers themselves as well as their agents. Found at operabase.com, it was created in 1996 by English software engineer and opera lover Mike Gibb. Initially a hobby site, it became his full-time occupation after three years. Opera magazine describes the Operabase website as "the most comprehensive source of data on operatic activity".