Who wrote the song "Je t'aime ... my non-plus"?

"Je t'aime… moi non plus" is a 1967 song written by Serge Gainsbourg for Brigitte Bardot. In 1969, Gainsbourg recorded the most well known version with Jane Birkin. The duet reached number one in the UK, and number two in Ireland, but was banned in several countries due to its overtly sexual content. In 1976, Gainsbourg directed Birkin in an erotic film of the same name.