ESF means Eurovision Song Contest
Actually, it's the hashtag for tweets about the Eurovision Song Contest. The Eurovision Song Contest is an annual presentation (and competition) of songs held every year in May since 1956. The festival is broadcast throughout Europe (and in some countries outside). Participate in any active member of the European Radio Union (EBU-UER), including members from outside Europe.
Eurovision 2013-All 39 Songs (RECAP) [YouTube] kOsbBabp15o [/youtube]